Vulnerability · Published Sep 30, 2026 · Assigned by CERT-PL

CVE-2026-74865Authentication Bypass in sogo_yhn

Critical 9.2

In plain English

A critical-severity authorization bypass via user-controlled key in sogo_yhn from YunoHost-Apps. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).

Severity (CVSS 4.0)9.2Critical

Exploit odds (30 days)0.4%top 67.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
YunoHost-Apps	sogo_yhn	0 – before 5.8.0~ynh9

Weakness: CWE-639 · Vector: 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

References

https://cert.pl/en/posts/2026/09/CVE-2026-74864 third-party-advisory
https://forum.yunohost.org/t/sogo-critical-vulnerability-fixed-in-5-8-0-ynh9/42699 issue-tracking