CVE-2025-52496
Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations occur.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
- EPSS
- 0.21% probability · 12th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-733
- Affected
- arm/mbed tls
- Source
- cve@mitre.org
EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-1.mdExploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/08/msg00013.html
- https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-1.mdExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.