PaperCut NG/MF vulnerabilities exploited in zero-day attacks
PaperCut warns of active zero-day exploitation chaining CVE-2026-81578 and CVE-2026-82078 for pre-auth remote code execution in NG/MF print management.
PaperCut Software confirmed attackers are chaining two vulnerabilities in PaperCut NG and MF: CVE-2026-81578, an improper access control flaw in the web management interface allowing unauthenticated configuration changes, and CVE-2026-82078, unsafe dynamic class loading in database connection utilities enabling arbitrary Java bytecode execution. Huntress reproduced a pre-authentication remote configuration takeover and full RCE chain against PaperCut NG 25.0.11.75758 and observed limited exploitation at two customers, including post-exploitation whoami and ver commands. The vendor released Emergency Patch Release 2 with additional hardening and urged restricting Application Server web access to trusted IPs. In 2023, Clop and LockBit affiliates abused CVE-2023-27350 and CVE-2023-27351 in the same software.
PaperCut Zero-Day Exploited in Attacks, Affecting All NG and MF Versions
PaperCut warns of actively exploited zero-day RCE chain CVE-2026-81578 and CVE-2026-82078 affecting all PaperCut NG and MF versions.
PaperCut alerted customers that attackers are actively exploiting a zero-day affecting all versions of PaperCut NG and MF print management software, with confirmed customer incidents and an ongoing investigation. Emergency patches were released for v25 and v26, and the flaw was later identified as an exploitation chain of CVE-2026-81578 and CVE-2026-82078 enabling remote code execution. Shared IoCs include suspicious post-exploitation activity from pc-app.exe and missing, truncated or deleted server.log files with specific database errors. Users with internet-exposed PaperCut Application Servers are urged to immediately restrict access to trusted IPs; in 2023, CVE-2023-27350 (CVSS 9.8) in the same products was exploited by Lace Tempest to deliver Cl0p and LockBit ransomware.
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.
PaperCut Zero-Day Under Active Attack: Emergency Patch Released
PaperCut warns that a zero-day in NG and MF print management products is being actively exploited, shipping emergency patches with no CVE assigned yet.
PaperCut Software confirmed active exploitation of a zero-day affecting PaperCut NG and MF, with confirmed customer incidents, and released emergency patches on Friday ahead of technical details or a CVE assignment. The company urges customers to restrict web access to trusted IP addresses, disconnect application servers from the internet, and watch for indicators including tampered or truncated server.log files, database error strings, and suspicious activity involving pc-app.exe. The article recalls the May 2023 exploitation of CVE-2023-27350 and CVE-2023-27351 by the financially motivated Lace Tempest group, a Clop ransomware RaaS affiliate, though no attacker attribution has been given for the current campaign.
Threat Brief: OWASSRF Vulnerability Exploitation
Unit 42 details active exploitation of Exchange SSRF flaws CVE-2022-41080/CVE-2022-41082 via the OWASSRF method, deploying the SilverArrow PowerShell backdoor.
Unit 42 documents OWASSRF, an exploit chain combining CVE-2022-41080 and CVE-2022-41082 to achieve remote code execution on Microsoft Exchange via Outlook Web Access, bypassing Microsoft's ProxyNotShell mitigations. Active exploitation was observed in late November and early December 2022, affecting at least eight organizations. Attackers authenticated to Exchange, then executed a PowerShell backdoor tracked as SilverArrow to create admin accounts, install AnyDesk, tunnel RDP via PuTTY Link, and dump LSASS memory for credential theft. Exploitation is isolated rather than mass-scale because authentication is required.
BGP hijack infecting networks caused by a comedy of errors that’s not funny at all
Attackers BGP-hijacked Softaculous IP space via Hetzner routing lapses to push malicious Virtualizor updates to hosting servers.
Unknown attackers hijacked the 162.55.80.0/24 prefix used by Softaculous' Virtualizor update service by abusing lax routing security at hosting provider Hetzner Online, announcing the range through AS6204, AS62390, and AS24940 with a forged but RPKI-valid origin. The hijack pulsed intermittently over roughly 33 hours, delivering modified update packages to Virtualizor servers, which lacked cryptographic code signing for updates. Softaculous says only a small number of servers were likely affected but cannot produce a definitive list, urging administrators to treat every Virtualizor server as in scope for checks.
GeoServer Zero-Day Is Already Being Probed. That’s the Problem
Unpatched GeoServer zero-day enabling SQL injection and possible RCE is being actively probed across exposed systems.
A zero-day in GeoServer's jsonArrayContains functionality allows unauthorized SQL injection and, in some configurations, remote code execution. Disclosed on August 12, 2026 without a CVE ID, it drew hundreds of exploitation probes from watchTowr within hours. No patch is available yet; GeoServer was previously mass-exploited via CVE-2024-36401.
Magento StyleSmuggler zero-day exploited to deploy Linux backdoor
StyleSmuggler zero-day in Magento and Adobe Commerce is actively exploited in the wild to deploy a Rust-based Linux backdoor; fix not yet released.
A zero-day dubbed StyleSmuggler affecting all versions of Magento and Adobe Commerce is being actively exploited, with the first observed incident on September 4 on a fully patched site. The exploit injects PHP code via Magento's template system through a fake 'failed-payment' email to achieve code execution, installing a Rust-based backdoor disguised as kworker/u:8:0 or fc-cache with a 30-minute cron job for persistence. The backdoor communicates via TLS/WebSockets or UDP port 123 masquerading as NTP traffic, checks TracerPid to detect tracing, and can receive remote commands. Adobe confirmed it is working on a fix with no timeline; Sansec recommends disabling GraphQL as mitigation and monitoring for suspicious cron entries and kworker or fc-cache processes. Magento is installed on more than 160,000 websites, including 14,000 of the top 1 million sites.