CVE-2025-49601 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-bi

What is CVE-2025-49601?

CVE-2025-49601 is a medium-severity vulnerability in mbedtls, published on 4 Jul 2025.

Official 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.

Weakness: CWE-125

Which versions are affected by CVE-2025-49601?

It affects 1 product.

Products include Trustedfirmware Mbed Tls.

How do I fix CVE-2025-49601?

Upgrade to a fixed version.

Is CVE-2025-49601 being exploited?

There is no known exploitation of CVE-2025-49601 in the wild and no public exploit code.

Other vulnerabilities in mbedtls

• CVE-2026-34875 Memory corruption in n/a Critical 9.8
• CVE-2024-49195 Memory corruption in n/a Critical 9.8
• CVE-2024-45158 Memory corruption in n/a Critical 9.8
• CVE-2024-45159 Auth bypass in n/a Critical 9.8
• CVE-2023-45199 Mbed TLS 3.2.x through 3.4.x before 3.5 has a Buffer Overflow that can lead to remote Code execution. Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2025-49601, DEBIAN-CVE-2025-49601, GHSA-h9v9-9rwj-pmq9, UBUNTU-CVE-2025-49601.