CVE-2025-49601: mbed tls Out-of-bounds Read (CVSS 4.8)

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.

Is your site exposed to CVE-2025-49601?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

4.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
arm	mbed_tls	3.3.0 — 3.6.4

References

Other References

https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-4.md

Frequently Asked Questions

What is 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-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. It has a CVSS v3.1 base score of 4.8 (MEDIUM).

How severe is CVE-2025-49601? +

CVE-2025-49601 has a CVSS v3.1 score of 4.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-49601? +

CVE-2025-49601 affects products from arm, specifically: mbed_tls. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-49601? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-29013

libcoap contains out-of-bounds read vulnerabilities in OSCORE Appendix B.2 CBOR unwrap handling where get_byte_inc() in src/oscore/oscore_cbor.c relies solely on assert() …

CVE-2026-53566

Out-of-bounds read vulnerability in Citrix Citrix Secure Access Client for Windows. This issue affects Citrix Secure Access Client for Windows: …

CVE-2026-3508

An Out-of-bounds Read vulnerability in the IOCTL handler in ASUS System Control Interface allows a local user to cause system …

CVE-2025-48520

An improper input validation vulnerability within the AMD Platform Management Framework (PMF) driver can allow a local attacker to read …

CVE-2026-3894

Out-of-bounds Read vulnerability in RTI Connext Professional (Core Libraries) allows Overread Buffers.This issue affects Connext Professional: from 7.4.0 before 7.7.0, …

CVE-2025-4098

Horner Automation Cscape version 10.0 (10.0.415.2) SP1 is vulnerable to an out-of-bounds read vulnerability that could allow an attacker to …

CVE-2025-49601