Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-81578

CVE-2026-81578HIGH

PaperCut MF/NG: Authentication Bypass

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   N   N   N   L   H   L    8.8   .8517   99.7   YES

AFFECTED
  Product         Versions     Fixed
  PaperCut MF/NG  unspecified  —

TIMELINE
  Aug 27  Reserved by PaperCut
  Aug 28  Published (CNA: PaperCut)
  Aug 31  EXPLOIT PUBLISHED — CVE-2026-81578 (PaperCut MF/NG). Public exploit reference added.
  Aug 31  ADDED TO KEV — CVE-2026-81578 (PaperCut MF/NG). Remediation due September 14, 2026.
  Sep 13  EXPLOIT PUBLISHED — CVE-2026-81578 (PaperCut MF/NG). Public exploit reference added.
  Sep 15  DUE DATE PASSED — CVE-2026-81578 (PaperCut MF/NG). CISA remediation deadline was September 14, 2026; still in catalog.

CWE-305 · CNA: PaperCut · CVSS v4.0 · 3 references · NVD status: Analyzed · KEV due September 14, 2026

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.

Lifecycle

Complete event history — 6 events, chronological
Date	Event	Detail
August 27, 2026	Reserved	Reserved by PaperCut
August 28, 2026	Published	Published (CNA: PaperCut)
August 31, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-81578 (PaperCut MF/NG). Public exploit reference added.
August 31, 2026	KEV ADDED	ADDED TO KEV — CVE-2026-81578 (PaperCut MF/NG). Remediation due September 14, 2026.
September 13, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-81578 (PaperCut MF/NG). Public exploit reference added.
September 15, 2026	DUE DATE PASSED	DUE DATE PASSED — CVE-2026-81578 (PaperCut MF/NG). CISA remediation deadline was September 14, 2026; still in catalog.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
PaperCut	PaperCut MF/NG	—	—	—

Weaknesses

CWE-305

References (3)

https://github.com/rapid7/metasploit-framework/pull/21842 [Issue Tracking, Patch]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578 [Patch, Third Party Advisory, US Government Resource]
https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ [Patch, Vendor Advisory]

Authoritative record: CVE-2026-81578 at cve.org

Vendors: papercut

Weaknesses: CWE-305

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-81578 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.