# CVE-2026-8794 — PaperCut NG/MF

> As of 2026-08-03, CVE-2026-8794 is a Medium-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in PaperCut NG/MF, CVSS v4.0 6.9, EPSS 0.6% (50.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-8794, most recently “PaperCut NG/MF Actively Exploited Zero-Day Vulnerability Affects All Supported Versions (No CVE Assigned)”.

**Last updated:** 2026-08-03

## What is CVE-2026-8794?

PaperCut NG/MF contains an observable timing discrepancy in its authentication component. An unauthenticated remote attacker can exploit this vulnerability to perform username enumeration by measuring response times during login attempts. The system executes a password hash comparison only when a valid account is supplied, creating a measurable timing oracle that reveals account existence.

The record classifies CVE-2026-8794 under weakness class [CWE-208](https://cwe.mitre.org/data/definitions/208.html). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 72 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 6.9 — Medium (derived from score) (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **EPSS (FIRST):** 0.6% probability of exploitation in the next 30 days, higher than 50.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-03

## Is CVE-2026-8794 being exploited?

Weaponised exploit code for CVE-2026-8794 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 39 in the Threadlinqs vulnerability feed.

- [H4zaz/CVE-2026-8794](https://github.com/H4zaz/CVE-2026-8794) (github)

## Affected products and versions

- [PaperCut](https://intel.threadlinqs.com/vendors/papercut): NG/MF

## How to fix CVE-2026-8794

No vendor patch reference has been recorded for CVE-2026-8794 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-8794

1 tracked threat in the Threadlinqs corpus references CVE-2026-8794, either in the campaign’s CVE list or as an indicator on the campaign record.

- [PaperCut NG/MF Actively Exploited Zero-Day Vulnerability Affects All Supported Versions (No CVE Assigned)](https://intel.threadlinqs.com/threat/TL-2026-2178) — CRITICAL · 2026-08-28

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [papercut.com](https://www.papercut.com/kb/Main/papercut-ng-mf-security-bulletin-3-aug-2026/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-8794
Full detection coverage and IOCs for threats exploiting CVE-2026-8794 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp