CVE-2026-34872
Description
A flaw was found in Mbed TLS and TF-PSA-Crypto. This vulnerability, stemming from improper input validation in the finite-field Diffie-Hellman (FFDH) key exchange, allows a remote attacker to force the shared secret into a small, predictable set of values. This lack of contributory behavior can compromise the security of protocols that rely on the uniqueness and unpredictability of shared secrets, potentially enabling further attacks.
Statement
An Important flaw exists in Mbed TLS and TF-PSA-Crypto due to improper input validation in the finite-field Diffie-Hellman (FFDH) key exchange. This allows a remote attacker to influence the shared secret to a small set of values, impacting protocols that rely on strong contributory behavior. Notably, the TLS protocol is not affected by this specific issue.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
Frequently Asked Questions
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