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Critical NetScaler Vulnerability Exploited in Attacks

CISA added critical Citrix NetScaler flaw CVE-2026-19490 (CVSS 9.3) to its KEV catalog after confirming exploitation of gateway and AAA virtual servers in the wild.

CISA warned that threat actors are exploiting CVE-2026-19490, a critical-severity flaw (CVSS 9.3) affecting NetScaler ADC and NetScaler Gateway appliances configured as a gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. Citrix patched the bug on August 19, and Rapid7 warned it is remotely exploitable without authentication. Sensor data from Previdian shows exploitation ongoing since at least September 3, one day after a public exploit appeared on GitHub, with matching requests observed from three IPs across three countries. CISA added the flaw to its Known Exploited Vulnerabilities catalog, giving federal agencies three days to patch under BOD 26-04.

SecurityWeekupdated · 5d agofirst · 6d agoExploit / PoC in the wild 5 sourcesCVE-2026-194902· 2 reads

SonicWall security advisory (AV26-853)

Canada's Cyber Centre relays a SonicWall advisory flagging vulnerabilities in NetExtender Linux Client 3.5 and earlier, urging administrators to apply updates as available.

The Canadian Centre for Cyber Security issued advisory AV26-853, noting SonicWall vulnerabilities affecting NetExtender Linux Client version 3.5 and earlier as of August 25, 2026. The relay provides no CVE identifiers or exploitation details and directs users and administrators to review SonicWall's security advisories and apply updates as they become available.

Canadian Centre for Cyber Security · 20d agoAdvisory

PEEP Turns Chrome and Edge Into Post-Compromise Backdoors for Host Command Execution

SOCRadar disclosed PEEP, a post-exploitation Chromium extension toolkit that turns Chrome and Edge into host-level backdoors via native messaging and C2 polling.

SOCRadar researchers detailed PEEP, a Chromium-based post-exploitation toolkit masquerading as a 'Smart Bookmarks' extension injected directly into Chrome and Edge profiles by forging Secure Preferences integrity values, bypassing Web Store checks. A native-messaging host binary (nm_host.exe) extends the browser agent to host-level command execution, file management, credential theft, and session hijacking, while the extension polls C2 endpoints at 206.237.30.232 or xfjcc.fun every 30 seconds over plaintext HTTP and exfiltrates browsing history, cookies, and tab metadata. PEEP is derived from the open-source RedExt red teaming framework, adds PowerShell persistence scripts, and includes a Linux-targeting Python script, suggesting cross-platform intent. The activity is unattributed but contains Chinese-language artifacts; a C2 /health endpoint showed 34 agent entries and 10 active sessions.

The Hacker News · 8d agoMalware in the wild

Wireshark 4.6.8 patches 28 security bugs, nine in file parsers

Wireshark 4.6.8 fixes 28 security bugs, including nine crash-prone capture file parsers, misdecoded 5G fields, and memory-safety issues.

Wireshark 4.6.8 fixes 28 security bugs spanning advisories wnpa-sec-2026-64 through wnpa-sec-2026-91, including nine crash bugs in file parsers such as pcapng, Endace ERF and Tektronix K12xx that trigger when opening capture files. Fixes cover dissectors for RDP, SSH, Kerberos, H.245, CMS, C12.22 and several Bluetooth protocols, plus unnumbered memory-safety issues like a stack buffer overflow in the K12/RF5 writer. The release also corrects eight misdecoded 5G NAS/5GSM fields and moves the Unix extcap path to /usr/libexec/wireshark/extcap.

Help Net Security · Aug 13, 2026Advisory

New infosec products of the week: August 21, 2026

Weekly product roundup covering NETSCOUT outbound DDoS mitigation, F5 AI Gateway enhancements, Intezer Workflows, and Tufin TOS 5.3.

NETSCOUT extended Adaptive DDoS Protection to automatically mitigate outbound attack traffic for service providers. F5 enhanced its AI Gateway and integrated it into the F5 AI Security Platform for unified AI access governance. Intezer launched Workflows, native automation and response inside its platform without a separate SOAR, and Tufin released Orchestration Suite 5.3 with AI-powered Segmentation Intelligence for multi-vendor environments.

Help Net Security · 26d agoTools

Agent-net Open Sources Webagent: A Go Harness That Turns Any Website into a Guarded AI Agent

Agent-net open-sourced Webagent, a Go harness turning websites into AI agents with code-enforced guardrails wrapping every tool call.

Agent-net released Webagent under Apache 2.0, a Go framework where a business fills in a declarative JSON spec, picks one provider for each of nine pluggable slots (retrieval, memory, guardrail, channel, secrets, presenter, model, action, observability), and runs webagent serve. Every tool the agent holds is wrapped by action.Guard so the chosen guardrail executes before any action runs and the model cannot bypass it. Live capabilities include OpenRouter/gateway LLM brains, MCP tools over Streamable HTTP, and Slack, WhatsApp, and HTTP channels; browser actions, OAuth-gated MCP, OTel export, and AgentNet identity/billing are not yet built. The project is v0 with a deferred-hardening list and cites arXiv 2511.19477 on an 85% versus 50% task-success gap attributed to architecture over model capability.

MarkTechPost · 1d agoAI tools & infra1

Vulnerabilities fixed in libxml2-2.15.4

libxml2 2.15.4 fixes an out-of-bounds read in xmlregexp's NXT macro plus several integer overflow and parsing flaws.

libxml2 2.15.4 (released September 1, 2026) includes security fixes: an out-of-bounds read in the xmlregexp NXT macro, missing overflow checks in dict.c, uri.c, and valid.c, an integer overflow in xmlIO before the writecallback, and an overflow check in xmlXPtrEvalXPtrPart. The release also propagates parseFlags in xmlXIncludeProcess and xmlXIncludeProcessTree. No CVE identifiers, exploitation, or severity ratings are given in the announcement.

oss-security · 11d agoVulnerability

GNU security advisory (AV26-923)

Canadian Cyber Centre advisory AV26-923 flags a stack overflow in GNU libextractor before v1.15 via OLE2 files.

The Canadian Centre for Cyber Security issued advisory AV26-923 on September 15, 2026, covering CVE-2026-91752, a stack overflow vulnerability in GNU libextractor versions prior to 1.15 triggered via OLE2 file parsing. The Cyber Centre encourages users and administrators to review the provided links and apply necessary updates as they become available.

Previously patched Citrix NetScaler flaw exploited in the wild (CVE-2026-8452)

Actively exploited Citrix NetScaler flaw CVE-2026-8452, patched in June, now added to CISA KEV; attackers deploy web shells and run discovery commands.

CISA added CVE-2026-8452, a memory overflow vulnerability in Citrix NetScaler ADC/Gateway, to its Known Exploited Vulnerabilities catalog on August 26, 2026, giving federal agencies until August 29 to remediate. Citrix disclosed and patched the flaw on June 30, 2026 in versions 14.1-72.61, 13.1-63.18, and 13.1-37.272. watchTowr Labs found the flaw can be chained into unauthenticated remote code execution and released a PoC on August 14. Previdian and Defused reported exploitation with web shells named x.php and z.php from at least three unique source IPs.

Help Net Security · 20d agoExploit / PoC in the wildCVE-2026-8452CVE-2015-3246CVE-2015-5287+3 CVEs

[webapps] Langflow 1.8.4 - Path Traversal to Remote Code Execution

A path traversal to remote code execution exploit for Langflow 1.8.4, a popular LLM application builder, was published on Exploit-DB.

Exploit-DB lists a proof-of-concept exploit chaining path traversal to remote code execution in Langflow 1.8.4, an open-source tool used to build LLM applications and agents. The chain allows an attacker to write arbitrary files outside the intended directory and achieve code execution on the host. The provided text does not include a CVE identifier or reports of exploitation in the wild, but RCE in a widely deployed AI tooling product is notable for defenders.

Exploit-DB · 16d agoExploit / PoC1

GitLab Vulnerability Exploited One Day After Disclosure

WatchTowr observed in-the-wild exploitation of critical GitLab path traversal CVE-2026-85706 one day after disclosure, letting unauthenticated attackers read arbitrary files.

WatchTowr detected the first in-the-wild probes for CVE-2026-85706 (CVSS 10.0), an unauthenticated path traversal in GitLab CE/EE that allows arbitrary file reads via a single HTTP request, and warns mass exploitation is likely. Affected versions include 18.7 before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2. The fresh patches also fix 17 other vulnerabilities, including CVE-2026-87719 (CVSS 9.9), an insecure deserialization flaw in the GraphQL subscription serializer exposing Advanced Search credentials, plus six high-severity bugs enabling RCE, CI/CD variable access, XSS, and denial of service.

SecurityWeekupdated · 1d agofirst · 4d agoExploit / PoC in the wild 18 sourcesCVE-2026-85706CVE-2026-877192· 1 read

Exploits in the Wild for Citrix ADC and Citrix Gateway Directory Traversal Vulnerability CVE-2019

Unit 42 confirmed in-the-wild exploitation of CVE-2019-19781, a critical Citrix ADC/Gateway directory traversal flaw enabling unauthenticated file access and RCE.

CVE-2019-19781, a CVSS 9.8 directory traversal vulnerability, affects all supported versions of Citrix ADC and Citrix Gateway. Unit 42 captured multiple exploitation attempts in the wild and identified scanning activity from roughly 700 Shodan-exposed hosts. The flaw stems from improper pathname handling in Apache, allowing unauthenticated attackers to read sensitive files like smb.conf or achieve remote code execution via crafted XML. Palo Alto Networks released Threat Prevention signatures 57497 and 57570 on January 7, 2020, while Citrix published advisories CTX267027 and CTX267679 with responder policy mitigations pending a late-January patch.

Palo Alto Unit 42 · Aug 17, 2026Exploit / PoC in the wildCVE-2019-19781

Critical NetScaler Flaw Can Bypass Authentication on Certain Gateway and AAA Servers

Citrix patches critical NetScaler Gateway and AAA authentication bypass CVE-2026-19490 (CVSS 9.3) plus a SIP ALG memory overflow flaw; exploitation attempts observed.

Citrix fixed CVE-2026-19490 (CVSS 9.3), an authentication bypass affecting customer-managed NetScaler ADC and Gateway appliances configured as Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual servers, and CVE-2026-19489 (CVSS 8.8), a memory overflow causing DoS when SIP ALG is enabled in Large Scale NAT groups. Updates are available in versions 14.1-73.32, 13.1-63.21, and corresponding FIPS/NDcPP builds, while Citrix-managed cloud services were already patched. The flaws were reported by Samarth Vashisht of JPMorgan Chase's penetration-testing team, and Previdian later observed 10 exploitation attempts against CVE-2026-19490 from six unique IP addresses in Australia, Germany, Japan, and the US, with no confirmed compromise.

Citrix urges customers to fix critical NetScaler authentication bypass (CVE-2026-19490)

Citrix patched a critical authentication bypass, CVE-2026-19490, in NetScaler Gateway and NetScaler ADC, urging customers to upgrade immediately.

Citrix has patched two flaws in NetScaler ADC and NetScaler Gateway. CVE-2026-19490 is a critical authentication bypass (CVSS v4.0 9.3) that works when the appliance is configured as an SSL VPN, ICA Proxy, CVPN, RDP Proxy Gateway or AAA virtual server, with additional conditions depending on firmware and SAML configuration. A second flaw, CVE-2026-19489 (CVSS 8.8), is a memory overflow that can cause denial of service when SIP ALG is enabled on LSN setups. Rapid7 had not observed exploitation as of August 19, 2026, but urged emergency patching; a signature-based mitigation is available via NetScaler Console.

VU#308749: Remote Code Execution and Arbitrary File Read Vulnerabilities in Kaltura Servers

Insecure deserialization in Kaltura's legacy HTML5 Player V2 (mwEmbed) allows arbitrary file read and remote code execution; Player V7 is unaffected.

CERT/CC issued VU#308749 for two flaws in Kaltura's HTML5 Player V2 library (mwEmbed/html5lib), both caused by the same insecure deserialization bug. The flaws enable arbitrary file read and remote code execution via the exposed mwEmbedLoader.php endpoint. Affected versions include html5lib v2.45, v2.103 and earlier, and other v2.x releases; the currently supported Player V7 is unaffected. No evidence of exploitation was cited.

CERT/CC Vulnerability Notes · 21d agoVulnerability

Survey of filesystem MCP servers: how the "sandboxed filesystem" boundary is enforced (one breach, four defended-by-design)

Survey finds one filesystem MCP server vulnerable to a symlink-based sandbox escape while four others are defended by design.

A survey of five filesystem MCP servers assessed how each enforces its path-confinement boundary against symlink escapes in recursive directory walkers. The iceener/files-stdio-mcp-server is vulnerable to a read-side sandbox escape. The other four are defended by design or make no confinement claim. The author describes the vulnerability class as small but real.

oss-security · 6d agoVulnerability

AL26-019 - Vulnerabilities impacting Citrix NetScaler ADC and NetScaler Gateway - CVE-2026-19490 and CVE-2026-19489

Canadian Cyber Centre alerts on Citrix NetScaler ADC/Gateway flaws CVE-2026-19490 (authentication bypass) and CVE-2026-19489 (buffer overflow), urging emergency patching.

The Canadian Centre for Cyber Security issued alert AL26-019 covering two Citrix NetScaler vulnerabilities disclosed in a vendor advisory on August 19, 2026. CVE-2026-19490 (CWE-288) allows a remote unauthenticated attacker to bypass authentication on appliances configured as a Gateway for SSL VPN, ICA Proxy, CVPN, RDP Proxy, or as an AAA virtual server. CVE-2026-19489 (CWE-120) is a classic buffer overflow that may cause memory overflow, unpredictable behavior, or denial-of-service conditions. Affected appliances are vulnerable when configured as a SAML IdP; fixed versions include 14.1-73.32, 13.1-63.21, and 13.1-37.277 for FIPS.

CVE-2026-19490: Critical Vulnerability Affecting Citrix NetScaler ADC and NetScaler Gateway

CVE-2026-19490 is a critical unauthenticated authentication bypass in Citrix NetScaler ADC and Gateway, remotely exploitable without user interaction.

An advisory published August 19, 2026 describes CVE-2026-19490, a critical authentication bypass affecting Citrix NetScaler ADC and NetScaler Gateway. The flaw carries a CVSS v4.0 base score of 9.3 and is remotely exploitable by unauthenticated attackers over the network without user interaction or elevated privileges. NetScaler ADC and Gateway are widely deployed enterprise products positioned at or near the network perimeter, providing load balancing, SSL/TLS offloading, and secure remote access. The text does not state whether exploitation has been observed in the wild.

Rapid7 Blog · 27d agoVulnerabilityCVE-2026-194901

[dos] Nmap 7.99 - Extension Header Integer Underflow

A proof-of-concept denial-of-service exploit for Nmap 7.99 leverages an integer underflow in extension header parsing to crash the scanner.

Exploit-DB lists a denial-of-service proof of concept targeting Nmap version 7.99. The flaw is an integer underflow when handling extension headers, which can crash the scanner. No exploitation in the wild or patch details are mentioned in the listing.

Exploit-DB · Aug 17, 2026Exploit / PoC1

[webapps] C-MOR 6.0104 - Directory Traversal

A directory traversal proof-of-concept for video surveillance software C-MOR version 6.0104 has been published on Exploit-DB.

Exploit-DB entry 52666 discloses a directory traversal vulnerability in C-MOR version 6.0104, a video surveillance platform. The issue is listed under web application vulnerabilities. No CVE identifier or exploitation evidence is included in the listing.

Exploit-DB · 16d agoExploit / PoC

Attackers plant remote access tools on compromised PaperCut servers

Attackers chained two PaperCut NG/MF zero-days for unauthenticated access, installing SimpleHelp and AnyDesk remote access tools on compromised servers.

An ongoing campaign exploits chained zero-days CVE-2026-81578 (improper access control) and CVE-2026-82078 (unsafe dynamic class loading) in internet-facing PaperCut NG and MF Application Servers, enabling authentication bypass and arbitrary Java bytecode execution. Post-compromise activity includes user and domain enumeration, payload download from sendit.sh, and silent installation of SimpleHelp and AnyDesk for redundant remote access; Defused observed CVE-2026-81578/CVE-2026-82078 exploit activity in honeypots since August 29, including data theft via Derby database dumps. Emergency patches were released August 28 and August 30, but 47% of roughly 2,500 PaperCut installs tracked by Huntress run v23 or older, for which no patch is available.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-820781

Citrix security advisory (AV26-645) – Update 3

Canada's Cyber Centre updates Citrix advisory as CVE-2026-8451 and CVE-2026-8452 in NetScaler ADC/Gateway are confirmed exploited in the wild.

The Canadian Centre for Cyber Security updated advisory AV26-645 on August 26, 2026, covering critical vulnerabilities in Citrix NetScaler ADC and Gateway (versions 14.1 before 14.1-72.61 and 13.1 before 13.1-63.18, plus FIPS builds). Open-source reporting indicates CVE-2026-8451 and CVE-2026-8452 are being exploited in the wild. Update 3 references related CISA action, and patched builds were released starting June 30, 2026.

CVE-2026-82617: Apache OpenNLP: ReDoS / stack exhaustion in RegexNameFinderFactory built-in EMAIL and URL patterns

Apache OpenNLP CVE-2026-82617: built-in EMAIL and URL regex name-finder patterns enable regular expression denial-of-service and stack exhaustion in affected releases.

CVE-2026-82617 affects Apache OpenNLP opennlp-core 3.0.0-M1 before 3.0.0-M6 and opennlp-tools 2.0.0 before 2.5.12. The DEFAULT_REGEX_NAME_FINDER.EMAIL and DEFAULT_REGEX_NAME_FINDER.URL patterns in RegexNameFinderFactory contain ambiguous nested quantifiers. Applications using these built-in finders on attacker-controlled input can be forced into regular expression denial of service or stack exhaustion. Fixes shipped in opennlp-tools 2.5.12 and 3.0.0-M6.

[Control Systems] National Instruments security advisory (AV26-914)

Canada's Cyber Centre relayed a National Instruments advisory covering improper access control and cleartext sensitive-information flaws in NI SystemLink and SystemLink Server.

Advisory AV26-914, dated September 11, 2026, notes that NI SystemLink and SystemLink Server prior to or equal to 2026 Q3 Patch 1 are affected by improper access controls and storage of sensitive information in cleartext. The Canadian Centre for Cyber Security urges users and administrators to review the vendor's links and apply available security updates.

Canadian Centre for Cyber Security · 4d agoAdvisory2

You’re Back In The Room (Citrix NetScaler Pre-Auth RCE CVE-2026-8452(?))

watchTowr Labs details a pre-authentication remote code execution flaw, tracked as CVE-2026-8452, in Citrix NetScaler appliances.

watchTowr Labs published technical analysis of a pre-authentication remote code execution vulnerability in Citrix NetScaler, tentatively assigned CVE-2026-8452. The CVE identifier is marked as provisional in the write-up. No confirmation of in-the-wild exploitation is provided in the available text.

watchTowr Labs · Aug 14, 2026Exploit / PoCCVE-2026-8452

CVE-2026-84939: Apache FreeMarker: A malformed locale may be exploitable for path traversal attacks

Apache FreeMarker CVE-2026-84939 permits path traversal via a malformed locale in template loading; fixed in FreeMarker 2.3.35.

A path traversal vulnerability in Apache FreeMarker's template loading mechanism can be triggered when an attacker controls a malformed locale value. FreeMarker 2.2.0 through 2.3.34 are affected for both the org.freemarker:freemarker and freemarker-gae artifacts, while 2.3.35 is unaffected. No exploitation or CVSS details were included in the announcement.

oss-security · 7d agoVulnerabilityCVE-2026-84939

[webapps] Joomla JCE_2.9.15 - Remote Code Execution

A remote code execution proof of concept for Joomla Content Editor (JCE) 2.9.15 was published on Exploit-DB.

Exploit-DB added a webapps proof-of-concept for remote code execution affecting the Joomla Content Editor (JCE) component version 2.9.15. JCE is a widely deployed editor extension used on Joomla websites. The entry provides no CVE id and no evidence of in-the-wild exploitation.

Exploit-DB · Aug 17, 2026Exploit / PoC1

Access Control as Verified Parse Constraints

Researchers verify a class of EverParse validators that correctly enforce access-control policies, deploying a machine-checked enforcement gate on seL4.

The paper targets enforcement-code bugs in commercial security gateways by proving that forward-only, backtrack-free EverParse validators are verified recognizers for a bounded finite-state class that includes access-control decision functions with fixed-offset fields and bounded disjunction. Encoding a bounded policy language into a fixed-size byte buffer allows an SMT solver to verify the enforcement code once, covering all byte values, policies, requests, and sessions. Editing rule content over a fixed endpoint set requires no new proof, while adding endpoints reruns the toolchain. A deployment on the seL4 microkernel ensures every request passes through the gate and unverified components cannot corrupt the enforcement chain.

arXiv cs.CR · 5d agoResearch