ZeroHour

Source: SecurityWeek

20 stories in the last 30d

Root RCE Zero-Day in Cisco Secure Email Gateway Under Active Exploitation

Cisco warned customers on Monday that a zero-day vulnerability affecting Secure Email Gateway appliances has been exploited in the wild. The vulnerability is identified as CVE-2026-76461 and has a CVSS score of 9.8. Cisco describes it as an email parsing issue in AsyncOS software that can be exploited remotely and without authentication to execute arbitrary commands on the underlying operating…

SecurityWeekupdated · 2h agofirst · 17h agoExploit / PoC in the wild 15 sourcesCVE-2026-76461CVE-2025-20393CVE-2026-20079+1 CVEs

BlueMoon Exploit Kit Chains Recent Chrome, Windows Zero-Days

Proofpoint reports multiple espionage groups rapidly adopting BlueMoon, a new exploit kit chaining Chrome and Windows zero-days.

Proofpoint identified a new exploit kit, BlueMoon, chaining two Chrome V8 zero-days (CVE-2026-85046, CVE-2026-87491) with a Windows ALPC privilege escalation zero-day (CVE-2026-85880), all patched between September 3 and September 2026 Patch Tuesday. China-linked Violet Typhoon (APT31) first used it on August 28 against US NGOs and mining/commodity trading firms; UNK_LateNight, UNK_DoubleCheck, and UNK_QuietRacket adopted it within days against targets in the US, Vietnam, Indonesia, and Singapore. The kit exploits the V8 defects for sandbox escape, fingerprints the host, and injects a CreateProcess stub into the Chrome broker process to download and execute a payload via curl. Development artifacts suggest the kit's creators may have used AI to build it, potentially lowering the barrier to exploit development.

SecurityWeekupdated · 12h agofirst · 3d agoExploit / PoC in the wild 20 sourcesCVE-2026-85046CVE-2026-87491CVE-2026-858804

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 · 22h agofirst · 4d agoExploit / PoC in the wild 17 sourcesCVE-2026-85706CVE-2026-877192· 1 read

Chinese Hackers Exploit Critical Tencent Software Flaw for One-Click Code Execution

China-linked UNC3569 actively exploited critical Sogou Input Method flaw CVE-2026-51990 for one-click system-level code execution, deploying the GrayRabbit backdoor.

Gen Threat Labs reports that China-linked threat actor UNC3569, possibly tied to contractor i-SOON, exploited critical CVE-2026-51990 in Tencent's Sogou Input Method, a Windows IME used by hundreds of millions, via crafted sgbiz URLs. The chain combines unvalidated command-line argument injection, unrestricted URL navigation, and an un-sandboxed Chromium 80 engine missing roughly six years of security patches. The exploit gives system-level code execution and was used to deploy the GrayRabbit backdoor, which provides a reverse shell, plugin loading, file upload to C2, and system info collection, and has appeared in UNC3569 intrusions since at least 2021. Tencent patched the issue in version 16.3.0.3498 via automatic update, but the outdated Chromium configuration reportedly remained unchanged as of September 10.

SecurityWeek · 1d agoExploit / PoC in the wild 2 sourcesCVE-2026-519901· 1 read

Organizations Warned of Cisco Secure FMC Exploitation

Cisco and CISA warn that critical FMC authentication bypass CVE-2026-20079 is actively exploited; CISA added it to the KEV catalog with a September 12 deadline.

Cisco and CISA flagged active exploitation of CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center allowing remote, unauthenticated attackers to run malicious scripts and gain root access via crafted HTTP requests. Cisco patched the flaw in early March and added IoCs in late July, but confirmed active exploitation in its September 9 advisory; CISA added it to the KEV catalog requiring federal remediation by September 12. Talos identified three activity clusters exploiting CVE-2026-20079 and CVE-2026-20316, including state-sponsored and financially motivated actors, and this is the third FMC vulnerability in KEV this year after CVE-2026-20316 and CVE-2026-20131.

SecurityWeekupdated · 1d agofirst · 5d agoExploit / PoC in the wild 13 sourcesCVE-2026-20079CVE-2026-20316CVE-2026-20131

Three JFrog Artifactory Flaws Exploited for Backdoor Deployment

Wiz reports multiple actors chaining three JFrog Artifactory auth flaws to gain admin and deploy backdoors; CISA added all three CVEs to KEV.

Wz reports threat actors exploiting CVE-2026-42018, CVE-2026-42016, and CVE-2026-82329 in self-hosted JFrog Artifactory instances to bypass authentication and gain administrative privileges. Between August 15 and September 8, 2026, multiple actors chained CVE-2026-42018 and CVE-2026-42016 to mint anonymous-user tokens, escalate privileges, create persistent admin accounts, install malicious plugins for code execution, and drop second-stage payloads. From early September, CVE-2026-82329 was exploited for configuration exfiltration, cluster key theft, token minting, and SSH key attachment to attacker-created accounts. CISA added all three CVEs to its KEV catalog, giving federal agencies two weeks under BOD 26-04 to patch to versions 7.161.20, 7.146.38, 7.133.29, 7.125.20, 7.117.28, or 7.111.21.

ConnectWise Patches ScreenConnect Vulnerability Exploited in Worm-Like Attacks

ConnectWise patched critical ScreenConnect flaw CVE-2026-84869 (CVSS 9.9) exploited since August 20 in worm-like attacks; CISA added it to KEV.

ConnectWise released urgent patches for CVE-2026-84869 (CVSS 9.9), a missing authorization and improper privilege management flaw in ScreenConnect allowing file transfer and execution through active remote sessions without host confirmation. Huntress reported in-the-wild exploitation since August 20, with attackers using rogue ScreenConnect clients to push four VBScript files for persistence and worm-like propagation to other ScreenConnect clients. The flaw is fixed in ScreenConnect 26.6.5, with disabling the TransferFiles permission as a temporary mitigation. CISA added the CVE to its KEV catalog, requiring federal agencies to patch within three days under BOD 26-04.

SecurityWeek · 1d agoExploit / PoC in the wild 3 sourcesCVE-2026-848691

PaperCut Flaws Exploited in AI-Powered Attacks

GreyNoise says a Russian-speaking actor used AI to build and deploy exploits hitting 440 PaperCut NG/MF deployments across 395 organizations in 48 countries.

Two PaperCut NG/MF zero-days, CVE-2026-82078 and CVE-2026-81578, disclosed August 27 and patched August 28, enable unauthenticated authentication bypass and remote code execution. GreyNoise observed a Russian-speaking threat actor using AI to orchestrate attacks against 440 deployments in 48 countries, including 204 education-sector organizations, achieving domain admin at 12 victims. Attack paths included harvesting LSASS memory and registry secrets, mounted NoPac attacks, and adding accounts to Domain Admins, with AI automation shortening compromises to minutes or seconds.

SecurityWeekupdated · 4d agofirst · 4d agoExploit / PoC in the wild 9 sourcesCVE-2026-82078CVE-2026-81578

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

New ‘ShieldCrash’ Zero-Day Exploit Targets Microsoft Defender

Researcher Nightmare Eclipse released ShieldCrash, a Microsoft Defender zero-day PoC bypassing ShieldBreak patches to gain System privileges on Windows.

The researcher known as Nightmare Eclipse released a PoC zero-day exploit dubbed ShieldCrash against Microsoft Defender on fully patched Windows systems. The exploit grants arbitrary file read with System privileges and can be used to drop the SAM database. It bypasses Microsoft's September 3 fixes for ShieldBreak (CVE-2026-69414), which itself bypassed patches for the RoguePlanet race condition (CVE-2026-50656). Microsoft has been contacted for comment and has not yet responded.

SecurityWeekupdated · 5d agofirst · 5d agoExploit / PoC 8 sourcesCVE-2026-50656CVE-2026-694141

Fortinet Code Execution Flaw Exploited in PivotC2 RAT Attacks

Threat actors exploit Fortinet heap-based buffer overflow CVE-2025-25249 to deploy PivotC2 RAT, infecting 178 devices and exfiltrating data from US targets.

SOCRadar reports exploitation of an unauthenticated remote code execution vulnerability, CVE-2025-25249 (CVSS 7.4), patched in January in FortiOS and FortiSwitchManager. Attackers scanned over 30,000 IP addresses, infected 178 devices with PivotC2 RAT, and at least two intrusions resulted in data exfiltration, primarily targeting US entities. SOCRadar attributes attacks to a likely Russian-speaking cybercrime actor and suggests the RAT was AI-assisted, in use since July 2026. CISA added the CVE to the KEV catalog with a three-day BOD 26-04 patch deadline for federal agencies.

SecurityWeekupdated · 5d agofirst · 5d agoExploit / PoC in the wild 4 sourcesCVE-2025-252491

Chrome 153 Patches Seventh Zero-Day of 2026

Google patches Chrome V8 zero-day CVE-2026-87491, exploited in the wild, marking the seventh exploited Chrome zero-day of 2026, in an update fixing 230 flaws.

Google released Chrome 153 with fixes for 230 vulnerabilities, including CVE-2026-87491, a medium-severity out-of-bounds write in the V8 JavaScript and WebAssembly engine that Google says is being exploited in the wild. It is the seventh zero-day patched in Chrome in 2026, following CVE-2026-2441, CVE-2026-3909, CVE-2026-3910, CVE-2026-5281, CVE-2026-11645 and CVE-2026-85046. The update also fixes five critical bugs (four in WebGL, one in Cast), 41 high-severity defects, and more than 180 medium/low issues, rolling out as 153.0.8010.36/.37 for Windows/macOS and 153.0.8010.36 for Linux.

SecurityWeek · 6d agoExploit / PoC in the wildCVE-2026-87491CVE-2026-2441CVE-2026-3909+4 CVEs

Microsoft Patches Record 974 Vulnerabilities, Including Two Exploited Zero-Days

Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two Windows zero-days exploited in the wild for privilege escalation.

Microsoft patched 974 vulnerabilities, its largest Patch Tuesday ever, including CVE-2026-85880, a heap buffer overflow in Windows ALPC allowing AppContainer sandbox escape to System, and CVE-2026-81963, a link-following flaw in the Windows Update Stack enabling local privilege escalation. Both were exploited as zero-days before the patch. ZDI's Dustin Childs says 20 of the fixed flaws are wormable, enabling unauthenticated remote code execution. The release also covers 723 Windows flaws and 222 Office bugs, plus fixes in Exchange, SharePoint, SQL Server, Azure and Exchange Server RCE (CVE-2026-55007).

SecurityWeek · 7d agoExploit / PoC in the wildCVE-2026-85880CVE-2026-81963CVE-2026-55007+5 CVEs

Adobe Patches Over 170 Vulnerabilities, Including Commerce Zero-Day

Adobe patched over 170 flaws, including in-the-wild zero-day CVE-2026-75650 (CVSS 10) in Adobe Commerce/Magento enabling unauthenticated RCE and web shell deployments.

Adobe released fixes for more than 170 vulnerabilities across Experience Manager, Acrobat Reader, Photoshop and other products. The Commerce zero-day CVE-2026-75650 (CVSS 10) allows unauthenticated code injection leading to remote code execution and has been exploited since September 4. Sansec reported multiple threat actors deploying backdoors and web shells via the bug, dubbed StyleSmuggler, which triggers injected code through Magento's Payment Transaction Failed Reminder email. Adobe also patched critical Campaign Classic command injection CVE-2026-82004 and two critical ColdFusion RCE flaws (CVE-2026-48273, CVE-2026-75746).

SecurityWeek · 7d agoExploit / PoC in the wildCVE-2026-75650CVE-2026-82004CVE-2026-48273+1 CVEs1

MikroTik Patches Critical Flaws Chained to Hack Routers

MikroTik patches six RouterOS flaws; two chained as MikroTrick are actively exploited via SSH to fully compromise exposed routers.

MikroTik released patches for six RouterOS vulnerabilities, including actively exploited MikroTrick chain: CVE-2026-67276 (9.2, SSH auth bypass) and CVE-2026-86060 (9.2, privilege manipulation), plus CVE-2026-67277 (8.8). CERT Poland confirms exploitation since September 2, creating an 'ops' account from IPs 82.192.72.4 and 103.102.31.18. Fixed in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21; Shadowserver found 120,000+ SSH-exposed MikroTik devices.

SecurityWeek · 7d agoExploit / PoC in the wildCVE-2026-67276CVE-2026-67277CVE-2026-67278+3 CVEs1

N-able Patches Critical Zero-Day in N-central

N-able patches critical unauthenticated RCE zero-day CVE-2026-86218 in N-central, exploited in the wild; on-premises admins must apply hotfix 2026.3 HF4.

N-able released an urgent hotfix (2026.3 HF4) for CVE-2026-86218 (CVSS 10), an unauthenticated RCE in N-central exploited as a zero-day. Scanning/exploitation attempts observed from IP range 23.234.64.0/18 starting September 4; admins should check logs for scanning and unrecognized new accounts. The hotfix supersedes patches for CVE-2026-86206 and CVE-2026-86207, which Huntress observed potentially chained in the wild to bypass authentication in production environments.

Nightmare Eclipse Drops CrowdStrike, Nvidia, Avast Zero-Day Exploits

Researcher Nightmare Eclipse released working zero-day PoCs for Avast, CrowdStrike Falcon, and Nvidia, prompting a Gen patch, CrowdStrike mitigation, and Nvidia investigation.

Security researcher Nightmare Eclipse released three zero-day exploits within a short window: PrettyPrague targeting the Avast sandbox for full system privileges (possibly affecting other GenDigital products including AVG and Norton), FalconFlank exploiting CrowdStrike Falcon Sensor's Office malicious macros remediation feature for privilege escalation, and GreenSection targeting an out-of-bounds memory write in a shared global memory section used by Nvidia user-mode components. GenDigital said it has fixed the Avast issue; CrowdStrike advised disabling the Microsoft Office File Suspicious Macro Removal policy setting; Nvidia said it is actively investigating the PoC. Kevin Beaumont reported that the Avast, CrowdStrike, and Kaspersky exploits work. The researcher previously released the HardBreacher privilege escalation zero-day in Kaspersky endpoint security, patched August 31.

SecurityWeek · 8d agoExploit / PoC

Adobe Commerce Zero-Day Exploited to Backdoor Online Stores

Sansec found attackers exploiting an Adobe Commerce/Magento zero-day (StyleSmuggler) since September 4 to deploy Rust backdoors on online stores.

Threat actors are actively exploiting a zero-day RCE in Adobe Commerce and Magento 2.4.7-2.4.9, injecting PHP code via generated failure reports and executing it through Magento's payment-failure email, with no user interaction required. Exploitation began September 4 and succeeds even against stores running the July and August 2026 patches; the Rust backdoor disguises itself as kworker/u:8:0 or fc-cache and hides C&C communication inside fake NTP replies. Adobe's September 8 Patch Tuesday updates may not include a StyleSmuggler fix.

SecurityWeek · 8d agoExploit / PoC in the wild

Modified ScreenConnect Clients Used in Worm-Like Campaign

Huntress warns of worm-like attacks using modified ScreenConnect clients to spread VBScript payloads; ConnectWise issued an advisory.

Campaigns starting in late August use social engineering, including Quick Assist abuse, to install rogue ScreenConnect clients that spawn wscript.exe and deploy four VBScript files for reconnaissance, staging, and PowerShell execution. The attackers persist via User Run Keys, attempt UAC bypass, install UltraViewer, and propagate the VBScript chain to other connected ScreenConnect endpoints. ConnectWise published an advisory about a file transfer behavior issue affecting cloud and on-premises ScreenConnect, with a CVE identifier and fix expected within a week; it recommends disabling file transfer meanwhile.

SecurityWeek · 8d agoExploit / PoC in the wild

Elementor Pro WordPress Plugin Vulnerability Exploited to Hack Sites

Attackers are actively exploiting critical file-upload flaw CVE-2026-32475 in Elementor Pro, hacking WordPress sites; Defiant has blocked over 190,000 exploit attempts since patching.

Defiant warns that attackers are exploiting CVE-2026-32475 (CVSS 9.8), an unauthenticated arbitrary file upload flaw in the Elementor Pro WordPress plugin's form submission handling, which affects all versions up to 4.2.1 and was patched in version 4.2.2 on August 19. Exploitation began immediately after the fix shipped, with Defiant blocking over 190,000 exploit attempts to date; roughly two-thirds of Elementor's 10 million installations still ran a vulnerable version as of September 4. Successful exploitation writes attacker-controlled PHP files to /wp-content/uploads/elementor/forms/ and can lead to full site compromise; administrators should check that directory for PHP files and review requests to /wp-admin/admin-ajax.php.

SecurityWeek · 10d agoExploit / PoC in the wildCVE-2026-32475