ZeroHour

Source: SecurityWeek

12 stories in the last 7d

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 · 8h agofirst · 23h 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 · 18h 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 · 1d 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 14 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 8 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