Vulnerability · Published Apr 1, 2026 · Assigned by mitre
CVE-2026-34875
Critical 9.8
In plain English
A critical-severity buffer overflow in the mbedtls package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.4%top 68.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | mbedtls | no fix listed | DEBIAN-CVE-2026-34875 |
| Debian:13 | mbedtls | 3.6.6-0.1~deb13u1 | DEBIAN-CVE-2026-34875 |
| Debian:14 | mbedtls | 3.6.6-0.1 | DEBIAN-CVE-2026-34875 |
| Ubuntu:25.10 | mbedtls | no fix listed | UBUNTU-CVE-2026-34875 |
| Ubuntu:26.04:LTS | mbedtls | no fix listed | UBUNTU-CVE-2026-34875 |
| Ubuntu:26.10 | mbedtls | no fix listed | UBUNTU-CVE-2026-34875 |
Affected products (as reported)
Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H