Vulnerability in Papercut Mf
CVE-2026-81578
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.856 (99.7th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.016 · newest: 0.856 · change: +0.840
Affected products
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Public proof-of-concept exploits
References
- eb41dac7-0af8-4f84-9f6d-0272772514f4 (Patch, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Patch, Issue Tracking)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource, Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-81578?
- CVE-2026-81578 is a critical-severity vulnerability in Papercut Mf, classified under Authentication Bypass by Primary Weakness. CVSS score: 9.8/10. Published 2026-08-28.
- How severe is CVE-2026-81578?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-81578 known to be exploited?
- Yes. CVE-2026-81578 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-08-31), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.