---
title: "CVE-2026-81578: PaperCut MF/NG: Authentication Bypass | CubePath"
description: "An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions…"
language: en
source: https://cubepath.com/security/cve/CVE-2026-81578
---

# CVE-2026-81578: PaperCut MF/NG: Authentication Bypass | CubePath

## 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.

Official description from the CVE record, published by PaperCut. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-81578)

## Key data

### CVSS 4.0 High 8.8

Score published by PaperCut in the CVE record.

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

| Metric                              | Value   | What it means                                                                                                   |
| ----------------------------------- | ------- | --------------------------------------------------------------------------------------------------------------- |
| Attack vector                       | Network | The vulnerable component can be reached over a network, possibly from the Internet.                             |
| Attack complexity                   | Low     | No measurable action is needed to get around the system's built-in security controls. The attack is repeatable. |
| Attack requirements                 | None    | The attack works without any special deployment or execution conditions.                                        |
| Privileges required                 | None    | No account or privileges are needed.                                                                            |
| User interaction                    | None    | No action from any user is needed.                                                                              |
| Vulnerable system: confidentiality  | Low     | Limited effect on the secrecy of data.                                                                          |
| Vulnerable system: integrity        | High    | Serious or total effect on the trustworthiness of data.                                                         |
| Vulnerable system: availability     | Low     | Limited effect on availability.                                                                                 |
| Subsequent systems: confidentiality | None    | No effect on other systems' data secrecy.                                                                       |
| Subsequent systems: integrity       | None    | No effect on other systems' data trustworthiness.                                                               |
| Subsequent systems: availability    | None    | No effect on other systems' availability.                                                                       |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.84734 (84.7% probability)

Percentile

99.7%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

PaperCut NG/MF Missing Authentication for Critical Function Vulnerability

Added to the catalog

Aug 31, 2026

Federal due date

Sep 14, 2026

### CISA assessment as of Aug 28, 2026

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

yes

Technical impact

partial

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-305](https://cwe.mitre.org/data/definitions/305.html) Authentication Bypass by Primary Weakness

## Affected products

Products listed in the CVE record, as the CNA published them.

- PaperCut MF/NG

  - affected: before 24.1.10
  - affected: 25.0.0 up to before 25.0.13
  - affected: 26.0.0 up to before 26.0.5

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-s…](https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/)

## Timeline

1. ID reserved Aug 27, 2026
2. Record published Aug 28, 2026
3. Added to CISA KEV Aug 31, 2026
4. Record last updated Sep 13, 2026

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:08 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)