CVE-2025-27809

Name	CVE-2025-27809
Description	Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted certificates for arbitrary hostnames unless the TLS client application calls mbedtls_ssl_set_hostname.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1101499

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mbedtls (PTS)	bullseye	2.16.9-0.1	vulnerable
	bookworm	2.28.3-1	vulnerable
	trixie, sid	3.6.3-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mbedtls	source	(unstable)	3.6.3-1			1101499

Notes

[bookworm] - mbedtls <no-dsa> (Minor issue)
https://github.com/Mbed-TLS/mbedtls/issues/466
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2025-03-1/