CVE-2025-49601

Name	CVE-2025-49601
Description	In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_import_public_key does not check that the input buffer is at least 4 bytes before reading a 32-bit field, allowing a possible out-of-bounds read on truncated input. Specifically, an out-of-bounds read in mbedtls_lms_import_public_key allows context-dependent attackers to trigger a crash or limited adjacent-memory disclosure by supplying a truncated LMS (Leighton-Micali Signature) public-key buffer under four bytes. An LMS public key starts with a 4-byte type indicator. The function mbedtls_lms_import_public_key reads this type indicator before validating the size of its input.
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	1108788

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	fixed
	bullseye (security)	2.16.9-0.1+deb11u1	fixed
	bookworm	2.28.3-1	fixed
	trixie	3.6.3-1	vulnerable
	sid	3.6.4-2	fixed

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

Package	Type	Release	Fixed Version	Debian Bugs
mbedtls	source	bullseye	(not affected)
mbedtls	source	bookworm	(not affected)
mbedtls	source	(unstable)	3.6.4-1	1108788

Notes

[bookworm] - mbedtls <not-affected> (Vulnerable code not present)
[bullseye] - mbedtls <not-affected> (Vulnerable code not present)
https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-4.md