Skip to main content
VulnerabilityPublished

CVE-2026-25834: Mbed TLS · Improper Certificate Validation

Source CVE Database V5

0

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
6.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 1 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

AI-suggested

Until an official fix is released, users should monitor vendor communications for updates. No specific mitigation steps are provided in the available data.

Description

Mbed TLS versions from 3.3.0 up to 3.6.5 and 4.0.0 are affected by an algorithm downgrade vulnerability. This issue allows an attacker to force the use of weaker cryptographic algorithms during a TLS handshake. The vulnerability has a CVSS score of 6.5, indicating a medium severity level.

References

Community reviews

Loading reviews…