CVE-2025-49601: mbed mbedtls Out-of-bounds Read

Vulnerability summary

CVE-2025-49601 is a medium (CVSS 6.5) Out-of-bounds Read vulnerability in mbed mbedtls. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 23.7% of scored vulnerabilities.

Timeline

1. 04-07-2025
   PublishedVulnerability first disclosed.
2. 08-07-2025
   Last modifiedVulnerability information updated.

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.