PaperCut MF/NG: Authentication Bypass
Published Aug 28, 2026 ·Due Sep 14, 2026
8.8
HIGHCVSS 4.0
EPSS 85.17%
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.
Affected products
-
- Version 0StatusaffectedConstraints<24.1.10
- Version 25.0.0StatusaffectedConstraints<25.0.13
- Version 26.0.0StatusaffectedConstraints<26.0.5
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PaperCut | PaperCut MF/NG | unaffected |
|
- < 24.1.9
- ≥ 25.0.2 · < 25.0.12
- ≥ 26.0.2 · < 26.0.4
- < 24.1.9
- ≥ 25.0.2 · < 25.0.12
- ≥ 26.0.2 · < 26.0.4
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
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
1 other source (NVD) ▾
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
Date Added
Aug 31, 2026
Patch Due
Sep 14, 2026
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.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
ActiveAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Aug 31, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Aug–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (4 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 85.17% (0.85169) | 99.71th | v5 (v2026.06.15) |
| Sep 16, 2026 | 3.29% (0.03290) | 87.85th | v5 (v2026.06.15) |
| Sep 4, 2026 | 1.62% (0.01617) | 74.39th | v5 (v2026.06.15) |
| Aug 29, 2026 | 0.39% (0.00393) | 32.32th | v5 (v2026.06.15) |
References (3)
- https://github.com/rapid7/metasploit-framework/pull/21842 exploitIssue TrackingPatch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578 government-resourcePatchThird Party AdvisoryUS Government Resource
- https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ PatchVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://github.com/rapid7/metasploit-framework/pull/21842 | exploitIssue TrackingPatch | |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578 | government-resourcePatchThird Party AdvisoryUS Government Resource | |
| https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ | PatchVendor Advisory |
Change history (0)
No recorded changes yet.