CVE-2025-66442 Affecting mbedtls package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-UBUNTU2004-MBEDTLS-15926527
- published15 Apr 2026
- disclosed1 Apr 2026
Introduced: 1 Apr 2026
NewCVE-2025-66442 (opens in a new tab)How to fix?
There is no fixed version for Ubuntu:20.04 mbedtls.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mbedtls package and not the mbedtls package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2025-66442
- https://github.com/Mbed-TLS/TF-PSA-Crypto/releases
- https://github.com/Mbed-TLS/mbedtls/releases
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-compiler-induced-constant-time-violations/