CVE-2025-52497

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-04 · updated 2026-06-17
Weakness: CWE-193

Description

Mbed TLS before 3.6.4 has a PEM parsing one-byte heap-based buffer underflow, in mbedtls_pem_read_buffer and two mbedtls_pk_parse functions, via untrusted PEM input.

Affected products

mbedtls: before 3.6.4 — fixed in 3.6.4

How to fix

Upgrade to a fixed version: mbedtls 3.6.4. Check the vendor advisory for mitigations.

References

https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-2.md
https://lists.debian.org/debian-lts-announce/2025/08/msg00013.html

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