CVE-2025-49601

In MbedTLS 3.3.0 before 3.6.4, mbedtlslmsimportpublickey 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 mbedtlslmsimportpublickey 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 mbedtlslmsimportpublickey reads this type indicator before validating the size of its input.