CVE-2025-27809: mbed tls (CVSS 5.4)

Description

Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted certificates for arbitrary hostnames unless the TLS client application calls mbedtls_ssl_set_hostname.

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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-1188 CWE-1188

Affected Products

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

References

Other References

https://github.com/Mbed-TLS/mbedtls/releases https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2025-03-1/ https://github.com/Mbed-TLS/mbedtls/issues/466 https://mastodon.social/@bagder/114219540623402700

Frequently Asked Questions

What is CVE-2025-27809? +

Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted certificates for arbitrary hostnames unless the TLS client application calls mbedtls_ssl_set_hostname. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2025-27809? +

CVE-2025-27809 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-2025-27809? +

CVE-2025-27809 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-2025-27809? +

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.

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