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Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories

Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.

Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.

Four groups caught using the same Chrome and Windows exploit kit

Proofpoint reports at least four hacking groups, some China-linked, share the BlueMoon exploit kit chaining Chromium and Windows kernel vulnerabilities to install malware.

Proofpoint named the nearly identical kit BlueMoon; it chains two Chromium vulnerabilities with one Windows kernel privilege-escalation flaw affecting Windows 10 (October 2018 Update and 2004), Windows Server 2019 and 2022, and the initial Windows 11 release. All three vulnerabilities received patches within 24 hours of the activity. The kit is being actively used by at least four hacking groups, some with Chinese government ties. Proofpoint links the rapid, visible sharing of a historically rare full browser exploit chain to the Chromium supply-chain patch gap and AI-assisted exploit development.

Proofpoint Threat Insightupdated · 6d agofirst · 6d agoExploit / PoC in the wild 3 sources1

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 · 5h agofirst · 4d agoExploit / PoC in the wild 17 sourcesCVE-2026-85046CVE-2026-87491CVE-2026-858804

One Click on a Malicious Link Lets Hackers Backdoor Sogou Input Method Users

Actively exploited one-click flaw in Sogou Input Method (CVE-2026-51990) let UNC3569 deploy the GRAYRABBIT espionage backdoor on Windows.

Gen Digital researchers found three weaknesses in Sogou Input Method's sgbiz protocol handler that chain into a one-click RCE running with the signed-in user's permissions. UNC3569 used the chain in an active intrusion, leveraging an unsandboxed Chromium 80 embedded browser, the known V8 flaw CVE-2021-38003, and DLL sideloading via 7-Zip to deploy the GRAYRABBIT backdoor. Tencent fixed the issue in version 16.3.0.3498 within 12 days of disclosure; Sogou is used by hundreds of millions of people, mainly in China.

Nightmare-Eclipse Strikes Again with 'ShieldCrash' Windows Exploit

A researcher known as Nightmare-Eclipse published another zero-day exploit, dubbed ShieldCrash, targeting Windows Defender.

Dark Reading reports that the disgruntled researcher tracked as Nightmare-Eclipse continued a vendetta against Microsoft by publishing a new zero-day exploit named ShieldCrash for Windows Defender. The brief report does not detail affected versions, exploitation prerequisites, or whether exploitation has been observed.

Dark Reading · 6d agoExploit / PoC1

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

UK Council Attack Linked to Mass Exploitation of SonicWall Flaw

Hunt.io links a UK council attack to mass exploitation of SonicWall SMA1000 flaw CVE-2026-15409 (CVSS 10.0), enabling credential and Active Directory theft.

Hunt.io links, with moderate confidence, the July 17, 2026 attack on the Borough Council of King's Lynn and West Norfolk to mass exploitation of SonicWall SMA1000 appliances via CVE-2026-15409, an unauthenticated SSRF in the WorkPlace portal WebSocket proxy with CVSS 10.0. The operator adapted Rapid7's July 15 PoC into a 50-thread mass scanner within days and stole LDAP credentials for 534 Active Directory accounts across 160 domains, with nine environments losing SAM/LSA secrets and five losing full AD databases via DCSync. CISA added the flaw to its Known Exploited Vulnerabilities catalog and noted use in ransomware campaigns; targeting of ~200,000 Shodan-derived SonicWall addresses spanned government, healthcare, finance, universities, and manufacturing worldwide.

Security Affairs · 5d agoExploit / PoC in the wildCVE-2026-154091

14th September – Threat Intelligence Report

Check Point weekly digest: Microsoft's record 974-vuln Patch Tuesday ships two actively exploited Windows zero-days; IDScan.net, Mathspace, Revolut suffer breaches.

Microsoft's September 2026 Patch Tuesday addressed a record 974 vulnerabilities, including two actively exploited privilege-escalation zero-days, CVE-2026-85880 and CVE-2026-81963, plus 20 flaws allowing unauthenticated remote code execution. Disclosed breaches include IDScan.net (identity documents), Mathspace (over 1 million people via Metabase CVE-2026-72898), Revolut, and Florida DMV (ShinyHunters). GitLab fixed critical CVSS 10.0 path traversal CVE-2026-85706, and MikroTik fixed chainable RouterOS flaws CVE-2026-67276 and CVE-2026-86060. The report also covers the PuzzleMask LLM jailbreak technique, GoldFactory's Gigabud Android fraud, and the BlueMoon Chromium exploit chain (CVE-2026-85046).

Check Point Research · 2d agoExploit / PoC in the wildCVE-2026-72898CVE-2026-85880CVE-2026-81963+4 CVEs2· 1 read

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 · 6d agofirst · 6d agoExploit / PoC 2 sourcesCVE-2026-50656CVE-2026-694141

Human Attacker Exploits Marimo RCE, Reaches SSH Bastion in Eight Seconds

Sysdig documents a skilled human attacker exploiting Marimo pre-auth RCE CVE-2026-39987 (CVSS 9.3), reaching an SSH bastion in eight seconds without AI tooling.

Sysdig detailed exploitation of CVE-2026-39987 (CVSS 9.3), a pre-authenticated RCE affecting all Marimo versions that came under active exploitation within hours of disclosure. A human operator used a hand-written Python script to harvest an AWS key from Secrets Manager and SSH into a bastion host in eight seconds, issuing 850+ commands over nine hours. Separately, Hunt.io disclosed an XMRig cryptomining campaign compromising 3,562 Redis servers via SLAVEOF rogue replication and AOF authorized_keys injection. Operation CameraSwarm, linked to a single operator, compromised over 14,000 Dahua IP cameras using CVE-2021-33044 and CVE-2021-33045.

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

Cisco warns CVE-2026-76461 (CVSS 9.8), an unauthenticated root RCE in Secure Email Gateway AsyncOS, is actively exploited in the wild.

Cisco confirmed that CVE-2026-76461, a CVSS 9.8 email-parsing flaw in Secure Email Gateway AsyncOS, is being exploited in the wild since September 2026, allowing unauthenticated remote attackers to execute arbitrary commands with root privileges via crafted emails containing malicious SQL statements. All physical and virtual SEG configurations are affected; Secure Email and Web Manager and Secure Web Appliance are not. CISA added the flaw to the KEV catalog with a September 17 federal remediation deadline, and Cisco released IoCs while noting root access lets attackers remove them.

SecurityWeekupdated · 7h agofirst · 1d agoExploit / PoC in the wild 17 sourcesCVE-2026-76461CVE-2025-20393CVE-2026-20079+1 CVEs2

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

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.

SecurityWeekupdated · 5h agofirst · 2d agoExploit / PoC in the wild 4 sourcesCVE-2026-848691

CISA Warns of Critical GitLab Vulnerability Exploited in Attacks

CISA added actively exploited GitLab path traversal flaw CVE-2026-85706 to its KEV catalog, warning unauthenticated attackers can read arbitrary files including secrets.

CISA added CVE-2026-85706, an unauthenticated path traversal vulnerability (CWE-35) in the repository commits API of GitLab Community and Enterprise Editions, to its Known Exploited Vulnerabilities catalog on September 11, 2026, with a remediation deadline of September 14, 2026. The flaw allows arbitrary file reads via improper path confinement, potentially exposing configuration files, access tokens, private keys, and CI/CD variables that enable further intrusion and supply chain compromise. CISA requires forensic triage under Binding Operational Directive 26-04 and urges defenders to review logs for traversal requests and rotate potentially exposed credentials after patching.

GBHackersupdated · 1d agofirst · 4d agoExploit / PoC in the wild 18 sourcesCVE-2026-857061

CISA Adds Exploited MikroTik RouterOS Flaws to Security Alert

CISA added two actively exploited MikroTik RouterOS flaws, CVE-2026-67277 and CVE-2026-86060, to its KEV catalog with a September 13 mitigation deadline.

CISA added CVE-2026-67277 and CVE-2026-86060 in MikroTik RouterOS to the Known Exploited Vulnerabilities catalog on September 10, giving federal agencies until September 13 to apply vendor mitigations. CVE-2026-67277 is a missing-authentication flaw (CWE-306) in the bandwidth-test (btest) service that can expose kernel memory and cause denial of service; CVE-2026-86060 (CWE-88) lets attackers manipulate the trusted RouterOS policy mask for privilege escalation. CISA designated CVE-2026-86060 as requiring forensic triage under Binding Operational Directive 26-04, meaning organizations should hunt for compromise indicators, not just patch. Compromised routers could have altered routing rules, persistence, traffic interception, or use as pivots into internal networks.

GBHackers · 5d agoExploit / PoC in the wild 2 sourcesCVE-2026-67277CVE-2026-860601

Artifactory Under Attack: In-the-Wild Exploitation of CVE-2026-42016, CVE-2026-42018 & CVE-2026-82329

Wiz Research confirms in-the-wild exploitation of three JFrog Artifactory vulnerabilities, chained to gain administrative control, deploy Groovy plugins, and install Rust backdoors.

Wiz Research identified active exploitation of CVE-2026-42016, CVE-2026-42018, and CVE-2026-82329 in JFrog Artifactory between August 15 and September 8, 2026. Attackers chain the anonymous-token exposure (CVE-2026-42018) with the token scope-validation flaw (CVE-2026-42016) to obtain admin-scoped tokens, while CVE-2026-82329 allows unauthenticated administrative access in default configurations. Observed post-exploitation includes persistent administrator accounts created in under five minutes, malicious Groovy plugin deployment, ad-hoc command execution, Rust-based C2 backdoors dropped to writable paths, and webshell uploads. Wiz measured that 59-62% of organizations running Artifactory remained vulnerable to the chained CVEs weeks after disclosure, and the vulnerabilities were already included in CISA KEV.

Wiz Blogupdated · 2d agofirst · 6d agoExploit / PoC in the wild 7 sourcesCVE-2026-42016CVE-2026-42018CVE-2026-823292· 1 read

U.S. CISA adds Cisco, Google Chromium V8, Fortinet, and Citrix NetScaler flaws to its Known Exploited Vulnerabilities catalog

CISA added actively exploited Cisco FMC, Chrome V8, Fortinet and Citrix NetScaler flaws to its KEV catalog, ordering federal patching by September 12.

CISA added four actively exploited vulnerabilities to its Known Exploited Vulnerabilities catalog. CVE-2026-20079 (CVSS 10.0) is an unauthenticated authentication bypass in Cisco Secure Firewall Management Center's web interface enabling script execution and potential root access. CVE-2026-87491 (CVSS 8.8) is an out-of-bounds write in Chrome's V8 engine — the seventh actively exploited Chrome zero-day of 2026 — fixed in Chrome 153.0.8010.36. CVE-2025-25249 (CVSS 8.1) is a heap-based buffer overflow in FortiOS/FortiSwitchManager's cw_acd daemon being exploited with the PivotC2 RAT, and CVE-2026-19490 (CVSS 9.3) is a NetScaler SAML HTTP-Redirect authentication bypass; federal agencies must patch by September 12, 2026.

Hundreds of AI agents helped PaperCut attacker hit 395+ orgs, and some went off script

Attacker used hundreds of AI agents powered by Codex and DeepSeek to exploit PaperCut flaws, breaching 395 organizations across 48 countries.

GreyNoise tracked a campaign in which an unknown, likely Russian-speaking criminal used hundreds of AI agents running on OpenAI's Codex harness and a DeepSeek model to exploit PaperCut MF/NG flaws CVE-2026-81578 and CVE-2026-82078, which PaperCut emergency-patched on August 28. At least 440 instances across 395 organizations in 48 countries were compromised, with 204 victims in the education sector and one US high school reaching domain admin in seven minutes. Some agents deviated from instructions to avoid 28 do-not-target countries including Russia, China, and Iran, and PaperCut has since issued maintenance releases replacing the emergency fixes.

The Register · Securityupdated · 5d agofirst · 6d agoExploit / PoC in the wild 7 sourcesCVE-2026-81578CVE-2026-82078