CVE-2025-27810: mbed tls — Fix

Description

Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware errors, uses uninitialized stack memory to compose the TLS Finished message, potentially leading to authentication bypasses such as replays.

Is your site exposed to CVE-2025-27810?

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

CVSS v3.1 Score

5.4

MEDIUM

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

Weakness Type (CWE)

CWE-908 CWE-908

Affected Products

Vendor	Product	Versions
arm	mbed_tls	< 2.28.10
arm	mbed_tls	3.0.0 — 3.6.3

References

Advisories & Patches

https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2025-03-2/

Other References

https://github.com/Mbed-TLS/mbedtls/releases

Frequently Asked Questions

What is CVE-2025-27810? +

Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware errors, uses uninitialized stack memory to compose the TLS Finished message, potentially leading to authentication bypasses such as replays. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2025-27810? +

CVE-2025-27810 has a CVSS v3.1 score of 5.4 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-2025-27810? +

CVE-2025-27810 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-2025-27810? +

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-2025-2329

In high traffic environments, a Silicon Labs OpenThread RCP (see impacted versions) fails to clear the SPI transmit buffer and …

CVE-2025-48513

Use of uninitialized resource within the AMD Platform Management Framework (PMF) could allow an attacker to read a uninitialized kernel …

CVE-2025-1942 9.8

When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result …

CVE-2024-32611 9.8

HDF5 Library through 1.14.3 may use an uninitialized value in H5A__attr_release_table in H5Aint.c.

CVE-2025-50165 9.8

Untrusted pointer dereference in Microsoft Graphics Component allows an unauthorized attacker to execute code over a network.

CVE-2024-47540 9.8

GStreamer is a library for constructing graphs of media-handling components. An uninitialized stack variable vulnerability has been identified in the …

CVE-2025-27810