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Source: Help Net Security

19 stories in the last 30d

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Acronis backup plugin flaw exploited in targeted attacks (CVE-2026-87886)

Acronis warns CVE-2026-87886, an authenticated Linux privilege escalation flaw in its cPanel, WHM, and Plesk backup plugins, is under limited targeted exploitation; patches released.

Acronis disclosed CVE-2026-87886, a privilege escalation vulnerability caused by insecure file permissions in its backup plugins for cPanel, WHM, and Plesk, platforms popular among hosting providers and MSPs. Exploitation has been detected in the wild in limited, targeted attacks against cPanel & WHM deployments, with no exploitation observed on Plesk so far, and the low-complexity attack requires no user interaction. Fixes shipped last week: backup plugin version 1.9.3 HF3 for cPanel & WHM and extension version 1.8.11 for Plesk.

Help Net Securityupdated · 2h agofirst · 4h agoExploit / PoC in the wild 6 sourcesCVE-2026-87886

Cisco patches actively exploited email gateway zero-day (CVE-2026-76461)

Actively exploited zero-day SQL injection (CVE-2026-76461) in Cisco Secure Email Gateway allows unauthenticated root command execution; CISA ordered federal remediation by September 17.

Cisco confirmed attackers are exploiting zero-day CVE-2026-76461, an unauthenticated SQL injection in the email parsing logic of AsyncOS on Secure Email Gateway appliances (versions 16.5, 16.0, 15.5 and earlier) and Secure Email Cloud. Successful exploitation yields arbitrary SQL execution and root-level command execution on the underlying OS without user interaction. Cisco became aware of active exploitation in September 2025, has directly contacted affected cloud customers, and released fixed releases 15.5.5-014, 16.0.4-302, and 16.5.0-780. CISA added the flaw to its Known Exploited Vulnerabilities catalog and required federal civilian agencies to patch by September 17 and hunt for compromise.

Help Net Securityupdated · 16h agofirst · 1d agoExploit / PoC in the wild 15 sourcesCVE-2026-76461CVE-2025-20393

Cisco FMC bugs exploited by nation-state and ransomware actors (CVE-2026-20079, CVE-2026-20316)

Cisco Talos confirms nation-state (Sandworm) and ransomware (Qilin) actors actively exploit CVE-2026-20079 and CVE-2026-20316 in Secure Firewall Management Center.

CVE-2026-20079 is a critical unauthenticated authentication bypass in the FMC web interface allowing root-level script and command execution via crafted HTTP requests; CVE-2026-20316 stems from static hard-coded credentials enabling unauthenticated logins. Cisco Talos detailed three intrusion clusters: web shell and JAR deployment for credential theft, a Sandworm-attributed reverse shell and credential-harvesting implant, and a suspected Qilin ransomware operator chain. Cisco urges immediate hotfixes ahead of a comprehensive hardening release the week of September 16, or taking the FMC management interface offline.

Help Net Securityupdated · 2d agofirst · 6d agoExploit / PoC in the wild 13 sourcesCVE-2026-20079CVE-2026-20316

Week in review: Linux rootkit deployed on F5 BIG-IP APM devices, Cisco FMC bugs exploited

Weekly roundup: Cisco FMC and N-able N-central zero-days exploited in the wild, MikroTik RouterOS hijacks, Microsoft Patch Tuesday ships two exploited zero-days.

State-sponsored and financially-motivated attackers are actively exploiting CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center (FMC), alongside CVE-2026-20316. N-able issued an emergency hotfix for CVE-2026-86218, a critical pre-auth RCE in the N-central RMM platform exploited in the wild. CERT Polska disclosed six RouterOS vulnerabilities being chained to hijack internet-exposed MikroTik devices. Microsoft's September 2026 Patch Tuesday shipped a record patch count including two zero-days, while roughly 67,000 Trezor customers faced phishing after a shipping-partner breach and researchers privately disclosed a zero-click WeChat worm to Tencent.

Help Net Security · 3d agoExploit / PoC in the wildCVE-2026-20079CVE-2026-20316CVE-2026-862182· 1 read

AI agents exploited PaperCut flaws to breach 395 organizations

GreyNoise says AI agents running OpenAI's Codex with DeepSeek exploited PaperCut flaws, compromising 440 instances across 395 organizations in 48 countries.

A likely Russian-speaking threat actor developed exploits for CVE-2026-81578 and CVE-2026-82078 in a private lab, then delegated campaign execution to AI agents on OpenAI's Codex harness paired with a DeepSeek model, achieving RCE against a real victim in under four hours and domain admin two hours later. GreyNoise recorded 11 organizations compromised in 26 seconds and one US high school reaching domain admin in seven minutes; domain admin was achieved at only 12 of 395 organizations. Education was the hardest-hit sector with 204 victims; the US led with 98. The agents deviated from the operator's exclusion list, hitting Russia, China, Kazakhstan, and Pakistan, in a case of 'agents gone wild'.

Help Net Security · 5d agoExploit / PoC in the wild 8 sourcesCVE-2026-81578CVE-2026-82078

Google fixes yet another actively exploited Chrome zero-day (CVE-2026-87491)

Google patched actively exploited Chrome zero-day CVE-2026-87491, a V8 out-of-bounds write enabling sandboxed code execution, in Chrome 153.0.8010.36+.

Google fixed 230 Chrome vulnerabilities including CVE-2026-87491, a Medium-severity out-of-bounds write in the V8 JavaScript and WebAssembly engine that allows remote arbitrary code execution inside the sandbox via a crafted HTML page. Google confirmed an exploit exists in the wild; fixes shipped in Chrome 153.0.8010.36 and .37 for Windows and macOS and 153.0.8010.36 for Linux. The flaw was reported August 6, 2026 by Jihyeon Jeong of Seoul National University's Compsec Lab, earning a $2,500 bounty. It is the seventh actively exploited Chrome zero-day patched in 2026, following CVE-2026-2441, CVE-2026-3909, CVE-2026-3910, CVE-2026-5281, CVE-2026-11645 and CVE-2026-85046.

Help Net Security · 7d agoExploit / PoC in the wildCVE-2026-87491CVE-2026-2441CVE-2026-3909+4 CVEs

Google patches actively exploited Chrome zero-day (CVE-2026-85046)

Google patches actively exploited Chrome zero-day CVE-2026-85046, a V8 type confusion bug enabling sandboxed code execution via crafted HTML pages.

Google patched 12 Chrome vulnerabilities, including CVE-2026-85046, a CVSS 8.8 type confusion flaw in the V8 JavaScript and WebAssembly engine exploited in the wild. The bug, reported by researcher Salvatore Gulizia (Serotav) on August 4, 2026, allows arbitrary code execution inside the sandbox via a crafted HTML page; the researcher described it as a V8 compiler bug enabling arbitrary read/write on the JavaScript heap. Fixes shipped in Chrome 152.0.7977.82/.83 for Windows and macOS and 152.0.7977.82 for Linux, and this is the sixth Chrome zero-day Google has fixed in 2026.

Help Net Security · 8d agoExploit / PoC in the wildCVE-2026-85046CVE-2026-2441CVE-2026-3909+3 CVEs

Attackers use rogue ScreenConnect clients to spread malware

Attackers deploy rogue ScreenConnect clients that spread VBScript malware to newly connected machines while ConnectWise patches a file-transfer flaw.

ConnectWise confirmed a file transfer flaw in ScreenConnect affecting both Cloud and On-Premise deployments, with a CVE identifier and official fix promised within the week; administrators can mitigate immediately by disabling TransferFiles (or TransferFilesInSession) in each role. Huntress documented incidents where social engineering installs rogue ScreenConnect clients that spawn Windows Script Host processes running four VBScript files (1.vbs-4.vbs), add a WindowsServiceHost registry Run key, and propagate to newly connected endpoints. Payloads enabled host profiling, persistence, additional ScreenConnect installs, tunneling, security-control changes, and cryptocurrency mining. ConnectWise has not confirmed a technical link between the flaw and this campaign.

Help Net Security · 9d agoExploit / PoC in the wild

N-able patches critical N-central zero-day exploited in the wild (CVE-2026-86218)

N-able shipped an emergency hotfix for CVE-2026-86218, a pre-auth RCE zero-day in N-central RMM observed exploited in the wild.

N-able released Hotfix 4 for N-central 2026.3 on September 5 (build 2026.3.1.14), fixing CVE-2026-86218, a critical pre-authenticated remote code execution flaw in its RMM platform popular with MSPs. A private customer notice marked urgent said the zero-day 'has been observed being exploited in the wild,' while the public advisory said there were no confirmed production exploits. Huntress also flagged two high-severity vulnerabilities, CVE-2026-86206 and CVE-2026-86207, which allow authentication bypass and unrestricted access; they were patched the same weekend and were discovered by Rapid7's Stephen Fewer. N-able advised auditing N-central user accounts for unexpected users.

Help Net Security · 9d agoExploit / PoC in the wildCVE-2026-86218CVE-2026-86206CVE-2026-86207

Hackers exploit RouterOS flaws to hijack MikroTik devices without authentication

CERT Polska confirms attackers exploit chained MikroTik RouterOS SSH flaws to hijack devices without authentication; patches released in four RouterOS versions.

CERT Polska discovered six RouterOS vulnerabilities and confirmed active attacks chaining CVE-2026-67276 (CVSS 9.2, SSH authentication bypass caused by comparing only RSA key moduli) and CVE-2026-86060 (CVSS 9.2, privilege escalation via crafted usernames), dubbed MikroTrick. A third flaw, CVE-2026-67277 (CVSS 8.8) in the bandwidth-test service, can expose kernel memory or crash devices. Shadowserver counted about 122,500 MikroTik devices with SSH exposed; attackers created a privileged 'ops' account from IP 82.192.72.4, active since September 2. Fixes shipped in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21, adding startup configuration scanning with a 'Flagged' marker for unauthorized changes.

Help Net Security · 9d agoExploit / PoC in the wildCVE-2026-67276CVE-2026-86060CVE-2026-67277

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

Exploitation of Sangoma Switchvox flaw is underway (CVE-2026-9586)

Attackers actively exploit SQL injection flaw CVE-2026-9586 in unauthenticated Sangoma Switchvox endpoints, dropping reverse shells and second-stage cryptominer malware.

CVE-2026-9586, an unauthenticated SQL injection in Sangoma Switchvox SMB Edition 8.3, lets crafted HTTP POST requests execute arbitrary SQL against the backend PostgreSQL database. Horizon3 honeypots first saw exploitation on August 30, 2026 from IP 176.65.148.184, and dozens of additional source IPs have since joined with scanning payloads and second-stage malware that appears to be a cryptominer. The flaw was patched in Switchvox 8.4.0.2 on July 14, 2026; roughly 4,000 exposed instances exist, mostly in the United States, and exploitation is likely against most of them.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-9586

SonicWall SMA 1000 appliances under attack via zero-day flaws

SonicWall confirms active exploitation of zero-day SSRF (CVE-2026-83548) and command injection (CVE-2026-83549) flaws in SMA 1000 remote access appliances.

SonicWall confirmed attackers are actively exploiting two previously undisclosed vulnerabilities in SMA 1000 SSL VPN appliances, affecting physical and virtual models 6210, 7210, and 8200v but not SMA 100 appliances or SonicWall firewalls. CVE-2026-83548 is a pre-authentication SSRF in the Appliance Work Place interface allowing remote unauthenticated attackers to gain unauthorized access to sensitive functionality, while CVE-2026-83549 is an OS command injection in the Appliance Management Console that can yield remote code execution under specific conditions for authenticated admins. The vendor urged immediate hotfix deployment, IoC review with technical support, and re-imaging or redeployment plus password and TOTP token resets on confirmed compromise. This is the latest in a series of zero-day attacks against SMA 1000 appliances following waves in late 2025 and June-July 2026.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-83548CVE-2026-83549

Nearly 22,000 Microsoft Exchange servers remain exposed to critical security flaw (CVE-2026-62911)

About 22,000 Microsoft Exchange servers remain unpatched against critical auth bypass CVE-2026-62911 as a working exploit circulates online.

CVE-2026-62911 is a critical authentication bypass by capture-replay in Microsoft Exchange Server that allows an authorized attacker to elevate privileges over the network, with a CVSS score of 8.0. Microsoft patched the flaw on August 11, 2026, but Shadowserver Foundation scans show roughly 22,000 servers unpatched, with the US (6,200) and Germany (5,100) leading; BSI reports 85% of on-premises Exchange servers in Germany are still vulnerable. The Netherlands' NCSC-NL flagged that a working exploit is circulating, and Exchange 2016/2019 require the Extended Security Updates program for fixes.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-62911CVE-2026-42897

PaperCut NG/MF vulnerabilities exploited in zero-day attacks

PaperCut warns of active zero-day exploitation chaining CVE-2026-81578 and CVE-2026-82078 for pre-auth remote code execution in NG/MF print management.

PaperCut Software confirmed attackers are chaining two vulnerabilities in PaperCut NG and MF: CVE-2026-81578, an improper access control flaw in the web management interface allowing unauthenticated configuration changes, and CVE-2026-82078, unsafe dynamic class loading in database connection utilities enabling arbitrary Java bytecode execution. Huntress reproduced a pre-authentication remote configuration takeover and full RCE chain against PaperCut NG 25.0.11.75758 and observed limited exploitation at two customers, including post-exploitation whoami and ver commands. The vendor released Emergency Patch Release 2 with additional hardening and urged restricting Application Server web access to trusted IPs. In 2023, Clop and LockBit affiliates abused CVE-2023-27350 and CVE-2023-27351 in the same software.

Help Net Security · 15d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-82078CVE-2023-27350+1 CVEs1

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

Critical Gitea vulnerability now exploited in the wild (CVE-2026-60004)

Attackers are actively exploiting critical Gitea RCE CVE-2026-60004 via the diffpatch endpoint, prompting CISA KEV addition and at least one cryptomining compromise.

CISA added CVE-2026-60004, a critical code injection flaw in Gitea's diffpatch endpoint, to its Known Exploited Vulnerabilities catalog after in-the-wild attacks. An attacker with repository write access, or an unauthenticated visitor on instances with open registration, can execute arbitrary shell commands as the Gitea OS user. A disclosed incident saw an automated scanner register an account and deploy a loader and cryptominer inside a Docker container within about 11 seconds, with no persistence mechanism found. Gitea patched the flaw in v1.27.1, and CISA ordered US federal civilian agencies to update by August 28, 2026.

Help Net Security · 21d agoExploit / PoC in the wildCVE-2026-60004

Unpatched Zimbra servers are falling to CVE-2026-73570 attacks

Attackers are exploiting unpatched Zimbra servers via CVE-2026-73570; 274 instances compromised, and CISA added the flaw to its KEV catalog.

The Shadowserver Foundation counted at least 274 compromised internet-facing Zimbra Collaboration Suite instances exploited through CVE-2026-73570, up from 155 on August 20. The unauthenticated code injection flaw affects servers with the optional zimbra-snmp package and SNMP notifications enabled, allowing arbitrary OS command execution via crafted SMTP requests. Synacor patched the issue in ZCS v10.1.20 on July 20, 2026, and at least 8,200 instances remain unpatched. CISA added the flaw to its Known Exploited Vulnerabilities catalog and gave US federal civilian agencies three days to remediate and check for compromise.

Help Net Security · 22d agoExploit / PoC in the wildCVE-2026-735701

Cyberattack forces UT San Antonio to delay start of fall semester

UT San Antonio delayed fall semester start by three days after a weekend cyberattack was caught at the network edge before core systems.

The University of Texas at San Antonio, which serves more than 42,000 students, moved its fall semester start from August 19 to August 24 after a weekend cyberattack on its academic network. Officials said the intrusion attempt was caught at the edge of the network before reaching core systems and that no evidence of data theft has been found. The university took systems and services offline for review, causing phone system outages and password reset tool delays. The incident follows the Instructure Canvas breach during spring finals week that exposed data tied to millions of students and staff worldwide.

Help Net Security · 28d agoExploit / PoC