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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

Four Nation-State Actors Used the Same Chrome Zero-Day Exploit Kit Within 12 Days

Proofpoint reports four nation-state actors, mostly China-nexus, adopted the BlueMoon Chrome and Windows zero-day exploit kit within 12 days, targeting US organizations.

Proofpoint tracked an exploit kit dubbed BlueMoon that chains CVE-2026-85046, a Chrome V8 type-confusion bug, with an unnamed V8 sandbox escape and CVE-2026-85880, a Windows kernel privilege escalation using ALPC and the Windows Notification Facility. The first observed use was by China-nexus TA412 (APT31, Violet Typhoon, JungleBamboo) on August 28, 2026 against US NGOs, mining companies, and commodity trading firms, followed by UNK_LateNight targeting US aerospace and defense companies on September 2. Both V8 bugs were patch-gap zero-days: the fix was committed to Chromium on August 7 but reached stable Chrome on September 3, enabling rapid weaponization from public patches. TA412's post-exploitation payload, GemStone, is a malicious browser extension posing as an AI-powered Google Gemini companion that captures keystrokes, cookies, screenshots, and browsing history via a Cloudflare Worker C2.

Security Affairsupdated · 1h agofirst · 6d agoExploit / PoC in the wild 19 sourcesCVE-2026-85046CVE-2026-858801

Hackers Deploy Hundreds of AI Agents to Compromise 440 PaperCut Servers

AI-agent campaign exploited PaperCut CVE-2026-81578 and CVE-2026-82078, compromising 440 servers at 395 organizations and reaching Domain Admin in 12.

GreyNoise tracked a likely Russian-speaking actor that used AI agents (OpenAI Codex, a DeepSeek model) to exploit an authentication bypass (CVE-2026-81578) and unsafe-reflection RCE (CVE-2026-82078) in PaperCut NG/MF starting August 31, 2026. At least 440 servers across 395 organizations in 48 countries were compromised, with one US high school going from initial access to Domain Admin in seven minutes. Escalation relied on LSASS and registry credential harvesting, pass-the-hash, the noPac technique (CVE-2021-42278/CVE-2021-42287), new Domain Admin accounts, and DCSync to steal NTDS.DIT data. Operators staged registry hives, used Ligolo tunneling and certutil Base64 encoding for exfiltration, and one attempt was blocked by Cloudflare WAF.

GBHackersupdated · 5d agofirst · 6d agoExploit / PoC in the wild 7 sourcesCVE-2026-81578CVE-2026-82078CVE-2021-42278+1 CVEs1

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

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

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.

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

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 · 5d agoExploit / PoC in the wild 7 sourcesCVE-2026-42016CVE-2026-42018CVE-2026-823292· 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 · 2d agoExploit / PoC in the wild 2 sourcesCVE-2026-519901· 1 read

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.