mbedtls: An issue was discovered in Mbed TLS versions from 2.19.0 up to 3.6.5, Mbed TLS 4.0.0
CVE-2026-34877 is fixed in mbedtls on 1 platform by DEBIAN-CVE-2026-34877 (version 3.6.6-0.1), released April 2, 2026. It is not reported as exploited. Patch Radar priority: Urgent.
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| mbedtls · Debian 14 | 3.6.6-0.1 | DEBIAN-CVE-2026-34877 | Apr 2, 2026 |
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