Vulnerability · Published Apr 1, 2026 · Assigned by mitre
CVE-2026-34874
High 7.5
In plain English
A high-severity null pointer dereference 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 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.3%top 78.4% 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 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | mbedtls | no fix listed | DEBIAN-CVE-2026-34874 |
| Debian:13 | mbedtls | 3.6.6-0.1~deb13u1 | DEBIAN-CVE-2026-34874 |
| Debian:14 | mbedtls | 3.6.6-0.1 | DEBIAN-CVE-2026-34874 |
| Ubuntu:25.10 | mbedtls | no fix listed | UBUNTU-CVE-2026-34874 |
| Ubuntu:26.04:LTS | mbedtls | no fix listed | UBUNTU-CVE-2026-34874 |
| Ubuntu:26.10 | mbedtls | no fix listed | UBUNTU-CVE-2026-34874 |
Affected products (as reported)
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H