NULL pointer dereference in Trustedfirmware Mbed TLS
CVE-2026-34874
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Trustedfirmware Mbed TLS — versions 4.0.0
Weakness classification (CWE)
References
- mbed-tls.readthedocs.io/en/latest/security-advisories/ (Vendor Advisory)
- mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory… (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34874?
- CVE-2026-34874 is a high-severity vulnerability in Trustedfirmware Mbed TLS, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-04-01.
- How severe is CVE-2026-34874?
- High severity. CVSS v3 base score is 7.5 out of 10.