CVE-2025-52496: Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations occur
Source GCVE Database
Not known to be exploited · CVSS 7.8 High : upgrade to 3.6.4 soon.
Data as of 29 Oct 2026, 22:52 UTC
Thin evidence
One scorer or none| CNA (mitre) | CVSS 3.1 | 7.8 |
|---|
- Patch
- Available – fixed in 3.6.4
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade mbed-tls/mbedtls to 3.6.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubmbed-tls/mbedtlspkg:github/mbed-tls/mbedtlsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.