# CVE-2026-74865 — YunoHost-Apps sogo_yhn

> As of 2026-09-30, CVE-2026-74865 is a Critical-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in YunoHost-Apps sogo_yhn, CVSS v4.0 9.2. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-74865, most recently “CVE-2026-74864 / CVE-2026-74865: Authentication bypass in YunoHost-Apps sogo_yhn (SOGo proxy-auth trust)”.

**Last updated:** 2026-09-30

## What is CVE-2026-74865?

sogo_yhn configures SOGo with a parameter "SOGoTrustProxyAuthentication=YES". This causes the password to be bypassed during HTTP Basic authentication. An unauthenticated attacker who provides the username of an existing user and any arbitrary password can successfully log in to that user's account. This issue was fixed in version 5.8.0~ynh9.

The record classifies CVE-2026-74865 under weakness class [CWE-639](https://cwe.mitre.org/data/definitions/639.html). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1 day ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 9.2 — Critical (derived from score) (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-30

## Is CVE-2026-74865 being exploited?

No public exploitation evidence for CVE-2026-74865 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-09-30. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- **YunoHost-Apps**: sogo_yhn

## How to fix CVE-2026-74865

No vendor patch reference has been recorded for CVE-2026-74865 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-2026-74865

1 tracked threat in the Threadlinqs corpus references CVE-2026-74865, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-74864 / CVE-2026-74865: Authentication bypass in YunoHost-Apps sogo_yhn (SOGo proxy-auth trust)](https://intel.threadlinqs.com/threat/TL-2026-2816) — CRITICAL · 2026-09-30

## Sources

Enriched from CVE.org, NVD. Last verified by Threadlinqs on 2026-10-01. This product uses the NVD API but is not endorsed or certified by the NVD.

**Third-party advisory**

- [cert.pl — third party advisory](https://cert.pl/en/posts/2026/09/CVE-2026-74864)

**Issue tracking and product pages**

- [forum.yunohost.org — issue tracking](https://forum.yunohost.org/t/sogo-critical-vulnerability-fixed-in-5-8-0-ynh9/42699)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-74865
Full detection coverage and IOCs for threats exploiting CVE-2026-74865 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp