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Fencer Vulns
high 7.8

CVE-2025-52496 json

Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations...

published 2025-07-04 16 mo ago modified 2026-07-23 3 mo ago also EUVD-2025-20081 , JLSEC-2025-228

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations occur. An attacker may be able to extract an AES key from a multithreaded program, or perform a GCM forgery.

Patch / fix

  • julia MbedTLS_jll 2.28.1010+0
  • Mbed mbedtls 3.6.4
  • mbedtls Debian 14, Debian 13 3.6.4-1

debian advisories DEBIAN-CVE-2025-52496

  • mbedtls Ubuntu Pro 18.04 LTS 2.8.0-1ubuntu0.1~esm1
  • mbedtls Ubuntu Pro 20.04 LTS 2.16.4-1ubuntu2+esm1
  • mbedtls Ubuntu Pro 22.04 LTS 2.28.0-1ubuntu0.1~esm1
  • mbedtls Ubuntu Pro 24.04 LTS 2.28.8-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2025-52496

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • mbedtls-2 openSUSE Leap 16.0 2.28.10-bp160.2.1
  • mbedtls-2 openSUSE Tumbleweed 2.28.10-5.1
  • mbedtls openSUSE Leap 16.0 3.6.6-bp160.1.1

opensuse advisories openSUSE-SU-2026:21864-1openSUSE-SU-2026:11790-1openSUSE-SU-2026:21144-1

  • mbedtls Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 3.6.4-r0
  • mbedtls3 Alpine 3.24 3.6.4-r0

alpine advisories ALPINE-CVE-2025-52496

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-52496 updated cvss 7.8

mbedtls: Mbed TLS AESNI Race Condition Vulnerability

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
16 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-1.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
julia MbedTLS_jll
<2.28.1010+0
2.28.1010+0

Affected products

  • Mbed mbedtls

Classification

Weakness
  • CWE-733 Compiler Optimization Removal or Modification of Security-critical Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.