cve.bz

CVE-2026-34872

9.1 criticalEPSS 0.2%

Critical (9.1) in arm. EPSS 0.2% chance of exploitation in the next 30 days.

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).

Severity

CVSS 3.1

9.1 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.2% chance of exploitation in the next 30 days; higher than 10% of CVEs (scores of 2026-10-31)
CWE
CWE-347
Published
Modified
Record from
the NVD, synced

Affected

References

Check your stackJSON