CVE-2026-81578

CRITICAL

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.

CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 8/28/2026Modified: 9/1/2026

Related Intelligence (2)

CRITICALZero Day

Metasploit Wrap Up: This One Goes to Sixteen!

This One Goes to Sixteen! Another banger from Metasploit with sixteen new modules, including ten exploit modules, with five on the CISA KEV list. Cisco, Papercut, Sonicwall, Jetbrains, and Langflow all have exploit modules, and not to be outdone, we even have a Metasploit scanner to watch the watchers! New module content (16) Elasticsearch ingest-attachment Apache Tika XFA XXE Local File Read Auth

CVE-2025-66516CVE-2025-54988
Rapid7
MEDIUMVulnerability

Attackers Exploit PaperCut Flaws to Steal Credentials From Schools and Universities

Threat actors are exploiting the newly disclosed PaperCut flaws to facilitate credential theft in attacks targeting the education sector in the U.S. and Europe. The Arctic Wolf Adversary Research Team said it observed attackers exploiting CVE-2026-81578 and CVE-2026-82078 – an authentication bypass and remote code execution chain – to conduct command execution and reconnaissance, as well as

CVE-2026-81578CVE-2026-82078
The Hacker News

References (3)

https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/PatchVendor Advisoryhttps://github.com/rapid7/metasploit-framework/pull/21842Issue TrackingPatchhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578PatchThird Party Advisory