CVE-2026-81578
Last modified
CVE-2026-81578 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 1.62% chance of exploitation in the next 30 days.
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.
Metrics
Exploitation Status
This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by .
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Papercut | Papercut Mf | < 24.1.9 |
| Papercut | Papercut Mf | >= 25.0.2, < 25.0.12 |
| Papercut | Papercut Mf | >= 26.0.2, < 26.0.4 |
| Papercut | Papercut Ng | < 24.1.9 |
| Papercut | Papercut Ng | >= 25.0.2, < 25.0.12 |
| Papercut | Papercut Ng | >= 26.0.2, < 26.0.4 |
References
- https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/Patch, Vendor Advisory
- https://github.com/rapid7/metasploit-framework/pull/21842Issue Tracking, Patch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578Patch, Third Party Advisory, US Government Resource
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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