CVE-2025-52496
published 2025-07-04CVE-2025-52496: 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…
PriorityP340high7.8CVSS 3.1
AVLACHPRNUINSCCHIHAN
EPSS
0.19%
8.7th percentile
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.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| arm | mbed_tls | < 3.6.4 | 3.6.4 |
| debian | mbedtls | < mbedtls 2.16.9-0.1+deb11u2 (bullseye) | mbedtls 2.16.9-0.1+deb11u2 (bullseye) |
| mbed | mbedtls | < 3.6.4 | 3.6.4 |
| mbed | mbedtls | >= 0 < 2.16.9-0.1+deb11u2 | 2.16.9-0.1+deb11u2 |
| mbed | mbedtls | >= 0 < 3.6.4-1 | 3.6.4-1 |
| mbed | mbedtls | >= 0 < 3.6.4-1 | 3.6.4-1 |
| mbed | mbedtls | >= 0 < 2.8.0-1ubuntu0.1~esm1 | 2.8.0-1ubuntu0.1~esm1 |
| mbed | mbedtls | >= 0 < 2.16.4-1ubuntu2+esm1 | 2.16.4-1ubuntu2+esm1 |
| mbed | mbedtls | >= 0 < 2.28.0-1ubuntu0.1~esm1 | 2.28.0-1ubuntu0.1~esm1 |
| mbed | mbedtls | >= 0 < 2.28.8-1ubuntu0.1~esm1 | 2.28.8-1ubuntu0.1~esm1 |
| msrc | azl3_qemu_8.2.0-17_on_azure_linux_3.0 | — | — |
| msrc | cbl2_qemu_6.2.0-24_on_cbl_mariner_2.0 | — | — |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
osv9.8CRITICAL
vendor_ubuntu9.8CRITICAL
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
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OSV
mbedtls vulnerabilities
osv·2026-03-25·CVSS 9.8
CVE-2021-44732 [CRITICAL] mbedtls vulnerabilities
mbedtls vulnerabilities
It was discovered that Mbed TLS incorrectly handled memory allocation
failures. A remote attacker could possibly use this issue to crash
the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu
20.04 LTS. (CVE-2021-44732)
Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted
inputs. A remote attacker could possibly use this issue to crash the
program, resulting in a denial of service. This issue only affected
Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)
It was discovered that Mbed TLS incorrectly handled the TLS
handshake. A remote attacker could possibly use this issue to
break the security guarantees of the TLS handshake.
(CVE-2025-27810)
Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly
documented t
OSV
CVE-2025-52496: Mbed TLS before 3
osv·2025-07-04·CVSS 7.8
CVE-2025-52496 [HIGH] CVE-2025-52496: Mbed TLS before 3
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.
GHSA
GHSA-qc26-g9mm-wmmf: Mbed TLS before 3
ghsa_unreviewed·2025-07-04
CVE-2025-52496 [HIGH] CWE-733 GHSA-qc26-g9mm-wmmf: Mbed TLS before 3
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.
Ubuntu
Mbed TLS vulnerabilities
vendor_ubuntu·2026-03-25·CVSS 9.8
CVE-2025-27810 [CRITICAL] Mbed TLS vulnerabilities
Title: Mbed TLS vulnerabilities
Summary: Several security issues were fixed in mbedtls.
It was discovered that Mbed TLS incorrectly handled memory allocation
failures. A remote attacker could possibly use this issue to crash
the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu
20.04 LTS. (CVE-2021-44732)
Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted
inputs. A remote attacker could possibly use this issue to crash the
program, resulting in a denial of service. This issue only affected
Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)
It was discovered that Mbed TLS incorrectly handled the TLS
handshake. A remote attacker could possibly use this issue to
break the security guarantees of the TLS handshake.
(CVE-2025-27810)
Linh Le
Microsoft
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 forg
vendor_msrc·2025-07-08·CVSS 7.8
CVE-2025-52496 [HIGH] CWE-733 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 forg
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.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update
Debian
CVE-2025-52496: mbedtls - Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compile...
vendor_debian·2025·CVSS 7.8
CVE-2025-52496 [HIGH] CVE-2025-52496: mbedtls - Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compile...
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.
Scope: local
bookworm: open
bullseye: resolved (fixed in 2.16.9-0.1+deb11u2)
forky: resolved (fixed in 3.6.4-1)
sid: resolved (fixed in 3.6.4-1)
trixie: resolved (fixed in 3.6.4-1)
No detection rules found.
No public exploits indexed.
2025-07-04
Published