PaperCut replaces emergency patches with a hardened release after 395 organizations were compromised
On September 10, 2026, PaperCut published NG/MF versions 26.0.5, 25.0.13, and 24.1.10, replacing three emergency patches and closing two actively exploited flaws, CVE-2026-81578 and CVE-2026-82078. If you are still running an emergency patch, move to the maintenance release now.
September 10, 2026. PaperCut published a maintenance release that replaces three emergency patches and closes two flaws already exploited in the wild. Versions 26.0.5, 25.0.13, and 24.1.10 of PaperCut NG/MF have passed the full QA process. Why it matters: GreyNoise and Blackpoint Cyber document a suspected Russian-speaking actor that has already breached 395 organizations across 48 countries, concentrated on the US education sector.
Two CVEs chained to bypass authentication and run code
The two vulnerabilities, CVE-2026-81578 and CVE-2026-82078, are chained in the wild to bypass authentication and then execute arbitrary code on vulnerable instances.
Chaining is what makes the pair dangerous in isolation. An authentication-bypass flaw alone opens a back door but does not yet hand over the keys; a code-execution flaw alone requires already being authenticated. Combined, the first manufactures access and the second turns it into control of the print server, with no valid-credential prerequisite. That is exactly the scenario GreyNoise documents in the field, and the one the three successive emergency patches tried to close on the fly. PaperCut had initially handled them with three successive emergency patches — Emergency Patch Releases 1, 2, and 3 — which also fixed two regressions and added hardening against potential attack chains.
This week’s maintenance release is different in kind. Where emergency patches ship without full validation, versions 26.0.5, 25.0.13, and 24.1.10 went through the standard test cycle. They bundle all the security fixes from the three emergency patches, plus additional hardening.
For a product deployed across schools, universities, and small businesses, the distinction matters: an emergency patch stops the bleeding, a maintenance release restores confidence in the update chain.
This is not the first time PaperCut has been at the center of large-scale exploitation. In 2023, CVE-2023-27350 — an authentication bypass in the same product — was mass-exploited by ransomware gangs weeks after the patch landed, again targeting schools and universities. History repeats, with one new detail: the exploitation cadence, measured in days, has only shortened.
A Russian-speaking actor, 395 organizations, hundreds of AI agents
GreyNoise and Blackpoint Cyber describe a suspected Russian-speaking actor that weaponized the two flaws to break into 395 organizations across 48 countries, mostly in the US education sector.
The execution method is the most alarming signal. 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.
The open question, raised by GreyNoise, is whether this actor is focused solely on developing access to hand off to other groups, or whether it will directly leverage that access for data theft or ransomware deployment. In either scenario, the already-compromised organization remains the victim.
The use of AI agents changes the nature of the threat. Where a campaign of this scale once required a team of human operators to enumerate targets, test access, and avoid entities to skip, automation lowers the marginal cost of every victim. For a defender, this means the gap between a patch being published and its exploitation at scale is now measured in hours, not weeks.
What the print infrastructure team should do
A PaperCut instance is not a niche exposure. PaperCut NG/MF manages print queues, quotas, and billing for tens of millions of users, often in institutions whose network is historically flat and lightly segmented. Code execution on the print server opens the door to the rest of the network.
The education sector concentrates the risk for a structural reason: print servers there are often run by a single school’s IT staff, with rare maintenance windows, thin security budgets, and strong seasonality. Between school holidays and the start of term, a patch can wait weeks — exactly what attacker automation now exploits.
- Identify your version — check whether you run 26.x, 25.x, or 24.x and compare against the patched releases;
- Move to the maintenance release — emergency patches are no longer the reference, releases 26.0.5, 25.0.13, and 24.1.10 supersede them and add hardening;
- Do not stay on an emergency patch — it closes the hole but lacks the additional QA-validated protections;
- Hunt the IP and IOCs — the indicator
45.142.193[.]132and the attack chains documented by GreyNoise and Blackpoint must enter your detection rules; - Segment the print server — a PaperCut instance does not need to reach the whole network, narrow its surface before the next flaw.
On the detection side, focus on two signals: abnormal authentication attempts on the admin console, and outbound connections from the print server to unknown addresses. Chaining the two flaws rarely shows up as a traffic spike; it shows up as a quiet privilege escalation followed by lateral movement. PaperCut’s authentication logs and the host’s network flows remain your best witnesses.
Verdict
PaperCut does not disclose the total number of exposed instances, but confirmed active exploitation combined with a heavily targeted education sector is enough to rank this update as urgent. The tipping point is not technical but organizational: teams that were applying emergency patches on the fly must now make the cutover to the stabilized release.
If you operate a PaperCut NG/MF instance, move to 26.0.5, 25.0.13, or 24.1.10 today, then check your logs for the IP 45.142.193[.]132 before considering the machine clean.
If you are in education or a small business without a dedicated security team, the real risk is not this flaw but the next one: segment the print server and automate its updates, because such a central product should no longer depend on manual intervention.