CVE-2026-34872

CVSS 9.1 CRITICALEPSS 0.2%CWE-347

Vexday Risk Score

28Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 9.1EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

01 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

An issue was discovered in Mbed TLS 3.5.x and 3.6.x through 3.6.5 and TF-PSA-Crypto 1.0. There is a lack of contributory behavior in FFDH due to improper input validation. Using finite-field Diffie-Hellman, the other party can force the shared secret into a small set of values (lack of contributory behavior). This is a problem for protocols that depend on contributory behavior (which is not the case for TLS). The attack can be carried by the peer, or depending on the protocol by an active network attacker (person in the middle).

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

Affected products

n/a · n/a

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References

https://mbed-tls.readthedocs.io/en/latest/security-advisories/https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-ffdh-peerkey-checks/