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CISA Warns of Citrix NetScaler Authentication Bypass Vulnerability Exploited in Attacks

CISA adds exploited Citrix NetScaler authentication bypass CVE-2026-19490 to the KEV catalog; federal agencies must patch by September 12.

CISA added CVE-2026-19490, a CWE-288 authentication bypass affecting NetScaler ADC and Gateway deployments configured as AAA virtual servers or Gateway services (including SSL VPN, ICA Proxy, and RDP Proxy), to the Known Exploited Vulnerabilities catalog. Citrix released fixes on August 19, 2026; honeypots recorded 56 attack attempts between September 3 and 8 after a public PoC, though no confirmed production compromises have been reported. Affected builds include 14.1 before 14.1-73.32 and 13.1 before 13.1-63.21; newer installations require SAML IdP configuration to be exposed.

Cyber Security Newsupdated · 6d agofirst · 6d agoExploit / PoC in the wild 6 sourcesCVE-2026-19490

Enterprises Warned of Attacks Exploiting WSO2 Vulnerability

Attackers are actively exploiting CVE-2026-5430 (CVSS 10), a WSO2 JWT authentication bypass, to access enterprise API credentials and sensitive data.

WatchTowr's honeypot network recorded the first exploitation attempt of CVE-2026-5430 on September 13, roughly two months after the CVE record was published in early August. The flaw, patched by WSO2 in April with an advisory in May, carries a maximum CVSS score of 10 and allows JWT authentication bypass via tokens signed with unsupported algorithms, enabling unauthorized access and full account takeover. A forged JWT observed in the wild granted access to API backend endpoints, credentials, and consumer keys and secrets for every registered application. WSO2's API Manager, API Control Plane, Traffic Manager, and Universal Gateway are affected, and the platform serves nearly 1,000 enterprise customers in banking, government, telecom, and logistics.

SecurityWeekupdated · 11h agofirst · 17h agoExploit / PoC in the wild 3 sourcesCVE-2026-54302· 1 read

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.

VU#943094: ONLYOFFICE ownCloud integration plugin contains a Server-Side Request Forgery (SSRF) vulnerability

ONLYOFFICE's ownCloud integration plugin 9.12 has an SSRF flaw (CVE-2026-84282) letting authenticated admins probe internal networks; no patch exists yet.

CERT/CC published VU#943094 for a server-side request forgery in Ascensio System SIA's ONLYOFFICE ownCloud integration plugin version 9.12, tracked as CVE-2026-84282. The /apps/onlyoffice/ajax/settings/address endpoint does not validate the user-supplied document server URL, so an authenticated administrator can make the ownCloud server send arbitrary requests to localhost and internal hosts. Differences in error responses (connection failures vs SSL/TLS errors) let attackers enumerate open and closed TCP ports for internal reconnaissance. The vendor could not be reached, so no official patch is available; CERT recommends disabling the plugin and applying egress filtering until a fix ships.

ZDI-26-562: (Pwn2Own) Home Assistant Green mDNS Server-Side Request Forgery Vulnerability

ZDI-26-562 details an unauthenticated, network-adjacent SSRF in the Home Assistant Green mDNS server, rated CVSS 5.4 and originally demonstrated at Pwn2Own.

A server-side request forgery in Home Assistant Green's mDNS service lets network-adjacent attackers initiate arbitrary server-side requests without authentication. The Zero Day Initiative assigned the flaw a CVSS 5.4 rating under advisory ZDI-26-562. The finding originated from Pwn2Own, and no exploitation in the wild is reported.

ZDI Published Advisories · Aug 12, 2026Vulnerability

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.

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

Microsoft Exchange Vulnerability CVE-2026-62911: What Administrators Should Do and How Zscaler Can Help

High-severity authentication bypass CVE-2026-62911 in Exchange Server has public exploit code; about 22,000 servers remain unpatched and internet-exposed.

Microsoft's August 2026 Patch Tuesday fixed CVE-2026-62911 (CVSS 8.0), an authentication bypass affecting Exchange Server 2016, 2019 and Subscription Edition. Successful exploitation lets an attacker with basic privileges take over all mailboxes on the targeted server, including reading and sending email and downloading attachments. As of September 1, Shadowserver identified roughly 22,000 unpatched, internet-exposed Exchange servers, including about 6,200 in the US and 5,100 in Germany. NCSC-NL confirmed working exploit code is publicly available, while CISA has not yet reported exploitation in the wild.

Zscaler ThreatLabz · 13d agoVulnerabilityCVE-2026-629112

ZDI-26-712: NoMachine nxhtd Server-Side Request Forgery Information Disclosure Vulnerability

ZDI disclosed CVE-2026-92210, an unauthenticated server-side request forgery in NoMachine's nxhtd server leading to information disclosure (CVSS 7.2).

ZDI published advisory ZDI-26-712 describing a server-side request forgery vulnerability in NoMachine's nxhtd server, tracked as CVE-2026-92210 with CVSS 7.2. Remote attackers can initiate arbitrary server-side requests without authentication, resulting in information disclosure. The advisory does not state whether exploitation has been observed or a patch released.

2026-011: Critical Vulnerabilities in SAP Kernel and NetWeaver Message Server

SAP patched two critical flaws, OVERPASS (CVE-2026-44756, CVSS 10.0) and S4GET (CVE-2026-58240), allowing unauthenticated attackers to execute OS commands on SAP hosts.

On SAP's September 2026 Security Patch Day, SAP released Security Notes 3747649 and 3759472 fixing two critical unauthenticated remote vulnerabilities found by Onapsis. CVE-2026-44756 ('OVERPASS', CVSS 10.0) is a memory corruption flaw in Extended Passport (EPP) deserialisation in the SAP Kernel; CVE-2026-58240 ('S4GET', CVSS 9.8) is a missing authentication check in the NetWeaver Message Server that lets attackers register as trusted cluster nodes. Successful exploitation of either can yield OS command execution as the SAP service account, leading to full system and business data compromise, and CERT-EU urges immediate patching. No in-the-wild exploitation is reported.

ZDI-26-563: (Pwn2Own) Home Assistant Green Simple Service Discovery Protocol Server-Side Request Forgery Vulnerability

ZDI disclosed a Pwn2Own SSRF flaw (CVSS 5.4) in Home Assistant Green's SSDP server, letting unauthenticated network-adjacent attackers trigger arbitrary server-side requests.

The Zero Day Initiative published ZDI-26-563 for a server-side request forgery in the Simple Service Discovery Protocol server on Home Assistant Green. The bug was demonstrated at Pwn2Own and allows network-adjacent, unauthenticated attackers to initiate arbitrary server-side requests on affected installations. ZDI rated the issue CVSS 5.4.

ZDI Published Advisories · Aug 12, 2026Advisory

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 · 28d agoVulnerabilityCVE-2026-194901

[webapps] flyto_core 2.26.7 - Server-Side Request Forgery

Exploit-DB published a server-side request forgery proof of concept for flyto_core 2.26.7.

Exploit-DB lists a proof-of-concept for server-side request forgery affecting flyto_core version 2.26.7. SSRF flaws can allow attackers to make arbitrary requests from the server toward internal resources. No CVE id is cited and no in-the-wild exploitation is reported.

Exploit-DB · Aug 17, 2026Exploit / PoC

Another Artifactory CVE under attack by AI agents or humans

Attackers are actively exploiting CVE-2026-82329, a critical JFrog Artifactory authentication bypass, minting admin tokens on exposed servers days after patch release.

CVE-2026-82329 is a CVSS 9.8 unauthenticated authentication bypass in JFrog Artifactory, disclosed Friday, that allows attackers to create new administrative credentials. watchTowr's honeypots recorded exploitation from a small number of IPs within days, including enumeration of users, groups, credential sets, and federated access topologies. Researchers urge urgent patching, credential rotation, and treating exposed instances as potentially compromised to prevent build-pipeline tampering and downstream supply-chain impact.

The Register · Security · 15d agoExploit / PoC in the wild 2 sourcesCVE-2026-82329

Japan’s Digital Agency Breach Exposes 240,000+ Users’ Personal Records to Hackers

Attackers exploited a patched VPN appliance flaw to breach Japan's Digital Agency shared government platform, exposing about 246,000 personal records.

Japan's Digital Agency disclosed on September 11 that attackers exploited a VPN appliance vulnerability to access the Government Solution Service (GSS), a shared IT platform across ministries, exposing roughly 246,000 personal records. The attacker was active since late May using a maintenance staffer's credentials, with suspicious activity detected June 25 and containment on July 9. Exposed data covers about 189,000 employees/public officials and 57,000 contractors; no My Number, bank, or pension data was included. The VPN flaw was medium severity with a patch already available, and the 78-day detection-to-disclosure gap has drawn scrutiny.

Cyber Security News · 1d agoData breach in the wild 2 sources

VU#889462: Casdoor authentication server is vulnerable to authorization bypass

Casdoor IAM versions 3.115.0 and earlier allow organization admins to bypass tenant isolation through inconsistent authorization checks, tracked as CVE-2026-15630.

CERT/CC published VU#889462 describing an authorization bypass in Casdoor, an open-source access management platform, affecting versions 3.115.0 and earlier. The flaw (CVE-2026-15630) stems from controllers ignoring the ?id= query parameter used for authorization decisions and acting on JSON body fields instead, letting a single-organization administrator perform unauthorized administrative actions against arbitrary organizations in multi-tenant deployments. Impact can escalate to complete tenant-isolation compromise and potential compromise of the entire Casdoor instance, including SSO/SAML disruption. No vendor patch is available because researchers could not reach Casdoor; mitigations include least privilege, MFA for admin accounts, and alerting on cross-organization administrative activity.

ZDI-26-627: Backblaze Personal Computer Backup bztransmit Link Following Denial-of-Service Vulnerability

ZDI published ZDI-26-627 for a local denial-of-service flaw (CVE-2026-19820, CVSS 6.1) in Backblaze Personal Computer Backup's bztransmit component.

The Zero Day Initiative published advisory ZDI-26-627 describing a link-following denial-of-service vulnerability in the bztransmit component of Backblaze Personal Computer Backup. Local attackers must first execute low-privileged code on the target system to trigger the condition. The issue carries a CVSS score of 6.1 and is tracked as CVE-2026-19820.

ZDI-26-588: Fabric.js loadFromJSON Server-Side Request Forgery Vulnerability

ZDI disclosed a server-side request forgery in Fabric.js loadFromJSON (CVE-2026-19504) that can leak sensitive information from affected implementations.

Zero Day Initiative advisory ZDI-26-588 describes a server-side request forgery vulnerability in the Fabric.js canvas library's loadFromJSON function. Exploitation requires interaction with the library and attack vectors vary by implementation, potentially exposing sensitive information. The issue is rated 4.0 on the CVSS scale and tracked as CVE-2026-19504. The advisory does not report exploitation in the wild.

U.S. CISA adds maximum-severity Oracle flaw to its Known Exploited Vulnerabilities catalog

CISA added actively exploited CVE-2026-21962, a CVSS 10.0 unauthenticated flaw in Oracle HTTP Server and WebLogic Proxy Plug-in, to KEV with an August 27 deadline.

CISA added CVE-2026-21962 (CVSS 10.0), an improper access control vulnerability in Oracle HTTP Server and the Oracle WebLogic Server Proxy Plug-in, to its Known Exploited Vulnerabilities catalog and ordered federal agencies to remediate by August 27, 2026. The unauthenticated flaw allows remote attackers with network access to create, delete, or modify critical data, potentially gain broad access, and cause a scope change to other systems; affected versions are 12.2.1.4.0, 14.1.1.0.0 and 14.1.2.0.0. CloudSEK honeypot data from January-February 2026 showed widespread exploitation of the flaw alongside older WebLogic RCEs including CVE-2020-14882/14883, CVE-2020-2551, and CVE-2017-10271.

Security Affairs · 22d agoExploit / PoC in the wildCVE-2026-21962CVE-2020-14882CVE-2020-14883+2 CVEs

CVE-2026-34486: Apache Tomcat Auth Bypass Vulnerability

SentinelOne details CVE-2026-34486, an Apache Tomcat EncryptInterceptor bypass exposing unencrypted cluster communications, with patches and workarounds available.

CVE-2026-34486 stems from an incomplete fix for CVE-2026-29146, letting network-positioned attackers bypass the EncryptInterceptor and read plaintext Tomcat cluster traffic, including session and application data between nodes. Affected versions 9.0.116, 10.1.53 and 11.0.20 are fixed in 9.0.117, 10.1.54 and 11.0.21. Workarounds include network-level encryption such as IPsec or VPN tunnels and isolating cluster communications to secured network segments.

Cisco Identity Services Engine Authorization Bypass Vulnerabilities

Cisco fixed authorization bypass flaws in ISE and ISE-PIC web management letting authenticated admins modify file descriptions via crafted HTTP requests.

Multiple vulnerabilities in the web-based management interface of Cisco Identity Services Engine and ISE Passive Identity Connector result from missing server-side validation of Administrator permissions. An authenticated remote attacker with valid Administrator credentials can submit crafted HTTP requests to modify descriptions of files on specific pages. Cisco has released software updates addressing the issues.

Cisco Security Advisories · 10h agoAdvisory 15 sources

Cisco Packaged Contact Center Enterprise and Cisco Unified Contact Center Enterprise Server-Side Request Forgery Vulnerability

Cisco patched an authenticated SSRF flaw in Packaged CCE and Unified CCE that lets credentialed users send arbitrary network requests from affected devices.

A server-side request forgery vulnerability caused by improper input validation of specific HTTP requests affects Cisco Packaged Contact Center Enterprise and Cisco Unified Contact Center Enterprise. An authenticated, remote attacker with valid user credentials can send crafted HTTP requests to make the device issue arbitrary network requests. Cisco has released software updates; no exploitation is reported in the advisory.

Cisco Security Advisories · 28d agoAdvisory

Hackers Exploit JFrog Artifactory Flaws to Bypass Authentication and Gain Admin Access

Wiz Research observes multiple attackers exploiting three JFrog Artifactory flaws, including default-configuration authentication bypass CVE-2026-82329, to gain admin access and deploy backdoors.

Attackers chain CVE-2026-42018 and CVE-2026-42016 to exchange anonymous JWTs for administrator-scoped tokens, or exploit CVE-2026-82329 directly via the registry join endpoint to obtain admin privileges under default configuration. Post-exploitation observed by Wiz includes persistent admin users created within five minutes, malicious Groovy plugins for command execution, and Rust-based backdoors dropped to /tmp, /var/tmp, and /dev/shm with C2 communications. Compromise exposes software artifacts, repository credentials, CI/CD integrations, and cluster secrets, creating supply chain risks. Fixed releases include 7.111.21, 7.117.28, 7.125.20, 7.133.29, 7.146.38, and 7.161.20.

GBHackersupdated · 2d agofirst · 5d agoExploit / PoC in the wild 7 sourcesCVE-2026-42016CVE-2026-42018CVE-2026-82329

ZDI-26-536: (Pwn2Own) Microsoft Windows http.sys Integer Overflow Local Privilege Escalation Vulnerability

ZDI discloses CVE-2026-62735, a Pwn2Own-demonstrated Windows http.sys integer overflow (CVSS 8.8) enabling local privilege escalation.

ZDI advisory ZDI-26-536 describes an integer overflow in Microsoft Windows http.sys, tracked as CVE-2026-62735 with a CVSS score of 8.8. The flaw was demonstrated at Pwn2Own and allows local attackers to escalate privileges on affected Windows installations. Exploitation requires first obtaining the ability to execute low-privileged code on the target system.

ZDI Published Advisories · Aug 11, 2026VulnerabilityCVE-2026-627351

U.S. CISA adds Metabase, Windows, and Cisco Secure Firewall flaws to its Known Exploited Vulnerabilities catalog.

CISA adds three actively exploited flaws—Cisco ASA/FTD DoS, Windows Winsock SYSTEM-level UAF, and Metabase SQL injection—to its Known Exploited Vulnerabilities catalog.

CISA added CVE-2026-20349 (CVSS 8.6, heap inspection flaw crashing Cisco ASA/FTD via crafted HTTP requests to the Remote Access SSL VPN service), CVE-2026-68820 (CVSS 7.0, use-after-free in the Windows afd.sys Winsock driver allowing SYSTEM-privilege code execution, actively exploited per Microsoft) and CVE-2026-72898 (CVSS 10.0, unauthenticated SQL injection in Metabase) to the KEV catalog. Metabase disclosed its cloud service was attacked with the 0-day, giving the intruder a path to administrator rights and stored credentials for connected databases; cloud instances were patched while self-hosted deployments need urgent updates. Under BOD 22-01, federal civilian agencies must patch by August 14, 2026, except CVE-2026-68820, due August 25.