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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

Human Attacker Hits Machine-Speed Exploitation of Marimo RCE

Sysdig details a human attacker chaining pre-auth RCE in Marimo (CVE-2026-39987) to AWS credentials and a bastion host in eight seconds.

Sysdig's Threat Research Team documented an intrusion where an operator exploited CVE-2026-39987, a pre-auth RCE in the Marimo notebook terminal WebSocket endpoint, gaining an interactive shell with no credentials. The attacker harvested AWS credentials from the process environment and Redis backend, retrieved an SSH private key from AWS Secrets Manager, and authenticated to an internet-reachable bastion host. The chain fired in eight seconds after roughly four hours of toolkit building, logging over 850 commands during a nine-hour session. The flaw, fixed in Marimo 0.23.0, has been on CISA's KEV catalog with a May 7, 2026 federal remediation deadline.

Infosecurity Magazineupdated · 1d agofirst · 2d agoExploit / PoC in the wild 4 sourcesCVE-2026-39987

Microsoft discloses two actively exploited zero-days among 974 vulnerabilities

Microsoft patches 974 flaws in record Patch Tuesday, including two actively exploited Windows zero-days enabling privilege escalation.

Microsoft's largest-ever Patch Tuesday addresses 974 vulnerabilities, with CVE-2026-81963 (Windows Update Stack) and CVE-2026-85880 (Windows Advanced Local Procedure Call) exploited before disclosure. Both zero-days carry CVSS 7.8 ratings and allow privilege escalation. More than 10% of the defects are rated critical, and researchers attribute the record volume to AI-assisted vulnerability discovery without a matching rise in active exploitation.

CyberScoop · 7d agoExploit / PoC in the wildCVE-2026-81963CVE-2026-85880

CVE-2026-34486: Apache Tomcat EncryptInterceptor Fail-Open Bypass

Technical analysis shows CVE-2026-34486 is a one-line fail-open regression in Tomcat Tribes enabling unauthenticated RCE via Java deserialization.

CVE-2026-34486 is a fail-open regression in Tomcat's Tribes EncryptInterceptor, introduced while fixing the CVE-2026-29146 padding-oracle flaw; Apache rated it Important and NVD scores it 7.5 High. Decryption failures are now forwarded to an unfiltered ObjectInputStream, and public PoC repositories demonstrate unauthenticated RCE on default port 4000 when clustering, the EncryptInterceptor, a reachable receiver and deserialization gadgets are all present. Affected releases 9.0.116, 10.1.53 and 11.0.20 are fixed in 9.0.117, 10.1.54 and 11.0.21; Tomcat 8.5 is unaffected.

⚡ Weekly Recap: VMware Exploits, Windows 0-Day, MCP Attacks, Browser Hijacks and More

Weekly recap: suspected China-nexus APT exploited VMware vCenter CVE-2026-59310, Lazarus used Windows zero-day CVE-2026-68820, and macOS flaw dropped Monero miners.

The week's top stories included a suspected China-nexus APT exploiting VMware vCenter CVE-2026-59310 (CVSS 9.8), a directory-traversal flaw enabling arbitrary code execution, with backdoors, reverse SSH and Babuk-derived ransomware deployed, per QUIRSO. NCSC-NL reported active exploitation of macOS Screen Sharing flaw CVE-2026-65400 (CVSS 9.8) to install Monero miners on systems with port 5900 exposed. Lazarus Group exploited Windows zero-day CVE-2026-68820 (CVSS 7.0) in Operation Dream Job, delivering ForestTiger and Troy backdoors to defense and aerospace targets. GeoServer patched a critical SQL injection flaw exploited within hours of disclosure, and Jamf analyzed the new Amnesia Stealer for macOS with live browser control.

The Hacker News · Aug 17, 2026Exploit / PoC in the wildCVE-2026-59310CVE-2026-65400CVE-2026-688201

CISA Warns Water Utilities: Find Your Exposed PLCs Before Attackers Do

CISA urged water utilities to secure internet-exposed PLCs after July 2026 attacks compromised over 100 US water and wastewater systems, suspected Iran-linked.

CISA's exposure-reduction guidance, published August 21, follows July 2026 attacks in which threat actors remotely accessed PLCs connected directly through cellular modems, changed device IP addresses and passwords, and in some cases disabled alarms and shutdown processes without notifying operators. Iran is the suspected actor, though officials stopped short of formal attribution. CISA recommends routing remote access through centrally managed secure gateways, phishing-resistant MFA, unique credentials, and external scanning of industrial protocols such as Modbus, EtherNet/IP, DNP3, BACnet and OPC UA.

Security Affairs · 20d agoExploit / PoC in the wild

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

Attackers exploit patched macOS Screen Sharing flaw to deploy cryptominer

Attackers actively exploit patched macOS Screen Sharing bug CVE-2026-65400 on systems with port 5900 exposed, gaining root to install a Monero cryptominer.

The Netherlands' National Cyber Security Centre (NCSC) reports active exploitation of CVE-2026-65400, an authentication flaw in macOS Screen Sharing that lets attackers authenticate without valid login credentials. Apple patched the issue in macOS Sequoia 15.7.9, Sonoma 14.8.9 and Tahoe 26.6.1, and the NCSC escalated its advisory on August 12 after proof-of-concept code went public and reports arrived of attacks on internet-exposed systems. In every reported case attackers obtained root access and installed a Monero crypto miner; users who cannot patch immediately are advised to disable Screen Sharing.

Help Net Security · Aug 17, 2026Exploit / PoC in the wildCVE-2026-65400