Detections
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CVE-2026-81578

high

Description

An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.

References

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578

https://www.securityweek.com/papercut-flaws-exploited-in-ai-powered-attacks/

https://www.helpnetsecurity.com/2026/09/11/ai-agents-papercut-ng-mf-attack-campaign/

https://thehackernews.com/2026/09/papercut-replaces-emergency-patches.html

https://www.theregister.com/security/2026/09/10/hundreds-of-ai-agents-helped-papercut-attacker-hit-395-orgs-and-some-went-off-script/5295650

https://www.bleepingcomputer.com/news/security/ai-powered-attack-exploited-papercut-flaws-to-hack-395-organizations/

https://thehackernews.com/2026/09/papercut-attacker-uses-hundreds-of-ai.html

https://www.greynoise.io/blog/ai-orchestrated-campaign-against-papercut-ng-mf

https://thehackernews.com/2026/09/attackers-exploit-papercut-flaws-to.html

https://securityaffairs.com/198476/hacking/papercut-flaws-exploited-in-attacks-on-u-s-and-european-schools.html

https://www.securityweek.com/papercut-exploitation-escalates-to-active-intrusions/

https://www.bleepingcomputer.com/news/security/recently-patched-papercut-zero-days-used-in-data-theft-attacks/

https://securityaffairs.com/198200/security/u-s-cisa-adds-papercut-ng-mf-flaws-to-its-known-exploited-vulnerabilities-catalog.html

https://www.securityweek.com/more-details-emerge-on-exploited-papercut-vulnerabilities/

https://www.helpnetsecurity.com/2026/08/31/papercut-attack-remote-access-tools/

https://www.databreachtoday.com/attackers-actively-exploit-flaws-in-papercut-ngmf-a-32696

https://www.cisa.gov/news-events/alerts/2026/08/31/cisa-adds-two-known-exploited-vulnerabilities-catalog

https://www.huntress.com/blog/papercut-actively-exploited

https://www.bleepingcomputer.com/news/security/papercut-releases-second-emergency-patch-for-exploited-flaws/

https://therecord.media/papercut-warns-of-hackers-using-printer-management-vulnerabilities

https://thehackernews.com/2026/08/attackers-chain-two-papercut-flaws-to.html

https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/

https://github.com/virologi-info/papercut-toolkit

https://github.com/yora1928/PaperCut-CVE-2026-81578-82078

https://github.com/rapid7/metasploit-framework/pull/21842

Details

Source: Mitre, NVD

Published: 2026-08-28

Updated: 2026-09-14

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 8.8

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00393

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest