CVE-2026-34875: Mbed TLS · Classic Buffer Overflow
Source CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Affects
- Mbed TLS through 3.6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
To mitigate CVE-2026-34875, organizations should: 1) Monitor for and apply official patches from Mbed TLS and TF-PSA-Crypto vendors as soon as they become available. 2) If patches are not yet available, implement strict input validation and bounds checking on public key export functions to prevent buffer overflow conditions. 3) Employ runtime protections such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) to reduce exploitation success. 4) Conduct thorough code audits and fuzz testing on cryptographic key handling routines to identify similar vulnerabilities. 5) Limit exposure by restricting access to cryptographic export functions to trusted components or users only. 6) Monitor logs and network traffic for anomalous activities related to cryptographic operations, especially those involving FFDH keys. 7) Educate developers and security teams about secure memory management practices in cryptographic implementations. These steps will help reduce the risk of exploitation and prepare organizations for timely remediation.
Description
An issue was discovered in Mbed TLS through 3.6.5 and TF-PSA-Crypto 1.0.0. A buffer overflow can occur in public key export for FFDH keys.