PaperCut Replaces Emergency Patches With Fixes for Two Actively Exploited Flaws
PaperCut shipped maintenance releases replacing emergency patches for two actively exploited flaws abused in AI-assisted attacks on 395 organizations.
PaperCut released PaperCut NG/MF versions 26.0.5, 25.0.13 and 24.1.10, superseding Emergency Patch Releases 1-3 for CVE-2026-81578 and CVE-2026-82078, which enable authentication bypass and arbitrary code execution on susceptible instances. GreyNoise and Blackpoint Cyber reported a suspected Russian-speaking actor weaponizing both flaws against at least 395 organizations in 48 countries, concentrated in the U.S. education sector. The campaign used hundreds of AI agents powered by OpenAI's Codex harness and a DeepSeek model, originating from IP 45.142.193.132, and avoided organizations in Russia, China, Hong Kong, Thailand and Iran.
- Maintenance releases 26.0.5, 25.0.13 and 24.1.10 replace emergency patches and add security hardening.
- CVE-2026-81578 and CVE-2026-82078 enable authentication bypass and arbitrary code execution.
- At least 395 organizations across 48 countries were targeted, mostly in the U.S. education sector.
- Attack automation used hundreds of AI agents via OpenAI Codex harness and a DeepSeek model.
- Unclear whether the actor sells access or plans data theft or ransomware follow-on.
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-82078 +1 in the same advisory: …81578 | Unsafe Reflection RCE in PaperCut NG/MF, Chained with Auth Bypass in Attacks CVE-2026-82078 is an unsafe dynamic class loading flaw (unsafe reflection, CWE-470) in the database connection utilities of PaperCut NG and PaperCut MF: the software instantiates a database driver class based on a configurable driver name without validating it against an allowlist of approved drivers. An attacker who can manipulate system configuration parameters can point that setting at classes of their choosing, causing the server to execute arbitrary Java bytecode residing on the application classpath in the security context of the PaperCut server process. On its own the issue is rated 9.4 (Critical) with high privileges required, but when chained with the companion authentication bypass CVE-2026-81578 it yields unauthenticated remote code execution on the print-management server. All PaperCut NG and MF deployments are in scope; affected version ranges were not specified in the available data, so administrators should consult PaperCut's advisory for fixed versions. The flaw is confirmed exploited in the wild as a zero-day: it was added to CISA's KEV catalog on 2026-08-31, and public reporting describes an AI-orchestrated campaign that compromised PaperCut servers at roughly 395 organizations (~440 servers), with EPSS currently at 1.7% (76th percentile). Do: Upgrade PaperCut NG and MF to the patched release specified in PaperCut's security advisory (exact fixed versions were not provided in this data), prioritizing internet-exposed print servers; the KEV listing means agencies must remediate per CISA BOD 26-04 or discontinue/mitigate per its cloud-service guidance. Restrict the PaperCut web interface from direct internet exposure (VPN/allowlist), review administrator accounts and database driver configuration for tampering, and hunt for post-exploitation activity, since this flaw is being actively chained with the authentication bypass CVE-2026-81578. | 9.4 group max | 2% | KEV |
| mass≈100,000+ organizations / plausibly millions of end users (vendor-cited install base); tens of thousands of on-prem servers with a smaller but significant… |
Full article340 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananSep 11, 2026Vulnerability / Cyber Attack
PaperCut on Thursday released a new security maintenance release that replaces all previously published emergency patches that were pushed to address two security flaws that have come under active exploitation.
The software development company said PaperCut NG/MF versions 26.0.5, 25.0.13 and 24.1.10 are now available for customers to download.
"These are Regular Maintenance Releases (MR) that have gone through complete QA testing," it said. "They contain all of the security fixes issued in Emergency Patch Releases 1, 2 and 3, plus additional security hardening, and they have been through our standard release testing process."
It's worth noting that the release supersedes the emergency patches that were shipped to address two security flaws as well as two regressions, along with various hardening and mitigation against potential attack chains.
The vulnerabilities, CVE-2026-81578 and CVE-2026-82078, have come under active exploitation in the wild to bypass authentication and execute arbitrary code on susceptible instances.
In one case highlighted by GreyNoise and Blackpoint Cyber, a suspected Russian-speaking threat actor has been found weaponizing the two flaws to break into at least 395 organizations in 48 countries, most of them concentrated in the U.S. education sector.
The attacks used hundreds of AI agents, powered by OpenAI’s Codex harness and a DeepSeek model, to target organizations at scale, while avoiding entities in Russia, China, Hong Kong, Thailand, Iran, and 23 other countries. The activity originates from the IP address "45.142.193[.]132."
"It is unclear if this actor is solely focused on access development to be handed off to other affiliated actors or if they will directly leverage their accesses to achieve follow-on objectives such as data theft or ransomware deployment," GreyNoise said.
In light of active exploitation efforts, it's imperative that users apply the latest fixes for optimal protection. PaperCut customers running an emergency patch build are advised to move to a maintenance release.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2026/09/papercut-replaces-emergency-patches.html