Which products and versions are affected by CVE-2026-81578?

Affected: Papercut Mf; Papercut Ng; PaperCut MF/NG versions >= 25.0.0. The full list is in the CVE brief.

Is CVE-2026-81578 being exploited in the wild?

It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 27, 2026.

Is CVE-2026-81578 in the CISA KEV catalog?

Yes. It was added on Aug 31, 2026 with a federal remediation due date of Sep 14, 2026.

Is there a public exploit for CVE-2026-81578?

Public exploit code is available.

Is there a fix for CVE-2026-81578?

Fixed versions are available, including PaperCut MF/NG 24.1.10, PaperCut MF/NG 24.1.10, 25.0.13, 26.0.5, PaperCut MF/NG 25.0.13.

How urgently should CVE-2026-81578 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2026-81578

HighExploitedPublic exploit

An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG.

Published Aug 28, 2026 · Updated Sep 14, 2026

Key Facts

Patch immediately

CVE-2026-81578 is a high-severity vulnerability (CVSS 8.8 v4) affecting Papercut Mf, Papercut Ng, PaperCut MF/NG.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 27, 2026. Public exploit code is available.
EPSS estimates a 86% probability of exploitation in the next 30 days.
Fixed versions are available, including PaperCut MF/NG 24.1.10, PaperCut MF/NG 24.1.10, 25.0.13, 26.0.5, PaperCut MF/NG 25.0.13.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v4

8.8

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

EPSS (30-day exploit likelihood)

86%

Higher than 99.7% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2026-81578 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

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.

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
CISA KEV	Aug 31, 2026	Sep 14, 2026	Not reported
Industry KEV feed	Aug 28, 2026	Sep 14, 2026	Not reported
CIRCL KEV	Aug 27, 2026	Sep 14, 2026	Not reported
ENISA EUVD	Aug 27, 2026	n/a	Not reported

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.

Affected Products

3 affected entries in total

Product	Affected versions	Fixed in
Papercut MfPapercut	See advisory	24.1.9
Papercut NgPapercut	See advisory	24.1.9
PaperCut MF/NG	>= 25.0.0	24.1.10, 25.0.13, 26.0.5

Patched Releases

PaperCut MF/NG

24.1.10, 24.1.10, 25.0.13, 26.0.5, 25.0.13, 26.0.5

Papercut Mf

24.1.9, 25.0.12, 26.0.4

Papercut Ng

24.1.9, 25.0.12, 26.0.4

Timeline

Added to CIRCL KEV
Aug 27, 2026
Added to ENISA EUVD
Aug 27, 2026
Publicly disclosed
Aug 28, 2026
Added to Industry KEV feed
Aug 28, 2026
Added to CISA KEV
Aug 31, 2026
Last updated
Sep 14, 2026

Weakness Type

CWE-305 Authentication Bypass by Primary Weakness

References

exploitVulnCheck exploitation report
exploitMSF papercut_ng_external_user_lookup_rce.rb
exploitVulnCheck exploitation report
exploitVulnCheck exploitation report
exploitVulnCheck exploitation report

8 more references in the full CVE brief

FAQ

Common Questions.

An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG.
Affected: Papercut Mf; Papercut Ng; PaperCut MF/NG versions >= 25.0.0. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 27, 2026.
Yes. It was added on Aug 31, 2026 with a federal remediation due date of Sep 14, 2026.
Public exploit code is available.
Fixed versions are available, including PaperCut MF/NG 24.1.10, PaperCut MF/NG 24.1.10, 25.0.13, 26.0.5, PaperCut MF/NG 25.0.13.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

Is CVE-2026-81578 Running On Your Attack Surface?

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