What’s Vulnerable › Vulnerabilities

CVE-2025-27809

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-03-25 · updated 2026-06-17
• Weakness: CWE-1188

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.

Affected products

• mbedtls: before 2.28.10 — fixed in 2.28.10
• TrustedFirmware Mbed TLS: from 3.0.0 before 3.6.3 — fixed in 3.6.3

How to fix

Upgrade to a fixed version: mbedtls 2.28.10; TrustedFirmware Mbed TLS 3.6.3. Check the vendor advisory for mitigations.

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

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