CVE-2025-49601

Publication date 4 July 2025

Last updated 8 October 2025

Ubuntu priority

Cvss 3 Severity Score

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mbedtls	25.10 questing	Vulnerable
	25.04 plucky	Ignored end of life, was needed
	24.10 oracular	Ignored end of life, was needs-triage
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected

Notes

hlibk

Versions below 3.3.0 are not affected

Severity score breakdown

Parameter	Value
Base score	4.8 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	None
Availability impact	Low
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L