CVE-2026-34877

State: Published
Severity: 9.8 Critical
Published: Apr 2, 2026
Updated: Apr 2, 2026
Reserved: Mar 31, 2026

Description

An issue was discovered in Mbed TLS versions from 2.19.0 up to 3.6.5, Mbed TLS 4.0.0. Insufficient protection of serialized SSL context or session structures allows an attacker who can modify the serialized structures to induce memory corruption, leading to arbitrary code execution. This is caused by Incorrect Use of Privileged APIs.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-250 Execution with Unnecessary Privileges
CWE-502 Deserialization of Untrusted Data

Affected Products

Product	Versions
n/an/a	n/aAffected

References

https://mbed-tls.readthedocs.io/en/latest/security-advisories/
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-serialized-data/

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