# CVE-2025-49601: mbedtls: 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...

CVE-2025-49601 is fixed in mbedtls on 1 platform, first by DEBIAN-CVE-2025-49601, released July 4, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-49601
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 4, 2025

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mbedtls Debian 13.5 (trixie) | 3.6.4-1 | [DEBIAN-CVE-2025-49601](https://patchblox.com/security/data/fix/linux/debian-cve-2025-49601.md) | Jul 4, 2025 |
| Linux | mbedtls Debian 14 | 3.6.4-1 | [DEBIAN-CVE-2025-49601](https://patchblox.com/security/data/fix/linux/debian-cve-2025-49601.md) | Jul 4, 2025 |
| Linux | mbedtls opensuse-leap 16.0 | 3.6.6-bp160.1.1 | [OPENSUSE-SU-2026:21144-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21144-1.md) | Jun 22, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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