CVE-2025-52496
Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.8
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.
- Record
CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-733
- Updated
- 2026-11-02
EUVDEUVD-2025-20081
7.8
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.
- Record
EUVD-2025-20081- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qc26-g9mm-wmmf
7.8
Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations...
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.
- Record
GHSA-qc26-g9mm-wmmf- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-733
- Updated
- 2026-11-02
NVD
7.8
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.
- Record
CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-733
- Updated
- 2026-11-02
OSVALPINE-CVE-2025-52496
7.8
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.
- Record
ALPINE-CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-03
OSV
7.8
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.
- Record
CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-733
- Updated
- 2026-11-02
Show 8 moreShow less
OSVDEBIAN-CVE-2025-52496
7.8
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.
- Record
DEBIAN-CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
OSVJLSEC-2025-228
7.8
Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler optimizations...
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.
- Record
JLSEC-2025-228- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
OSVROOT-OS-DEBIAN-12-CVE-2025-52496
7.8
CVE-2025-52496 in mbedtls - Patched by Root
Root has patched CVE-2025-52496 in the mbedtls package for Root:Debian:12. Multiple fixed versions available.
- Record
ROOT-OS-DEBIAN-12-CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-52496
7.8
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.
- Record
UBUNTU-CVE-2025-52496- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11790-1 No score
libmbedcrypto7-2.28.10-5.1 on GA media
These are all security issues fixed in the libmbedcrypto7-2.28.10-5.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11790-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:21144-1 No score
Security update for mbedtls
This update for mbedtls fixes the following issues:
Changes in mbedtls:
- Update to 3.6.6 (LTS maintenance update from 3.6.1); security fixes
accumulated across the 3.6.2-3.6.6 releases:
- CVE-2024-49195 (boo#1231708): buffer underrun in pkwrite when writing an opaque key pair
- CVE-2025-27809 (boo#1240051): certificate verification accepted arbitrary hostnames
- CVE-2025-27810 (boo#1240052): possible authentication bypass on failed memory allocation / hardware errors
- CVE-2025-47917 (boo#1246783): misleading memory management in mbedtls_x509_string_to_names()
- CVE-2025-48965 (boo#1246784): NULL pointer dereference after mbedtls_asn1_store_named_data()
- CVE-2025-49087 (boo#1246973): timing side channel in PKCS#7 padding removal
- CVE-2025-49600 (boo#1245808): unchecked return values in LMS verification allow signature bypass via fault injection
- CVE-2025-49601 (boo#1245809): out-of-bounds read in mbedtls_lms_import_public_key()
- CVE-2025-52496 (boo#1245810): race in AES-NI support detection can lead to AES key extraction or GCM forgery
- CVE-2025-52497 (boo#1245811): one-byte heap underflow when parsing PEM-encrypted material
- CVE-2025-54764 (boo#1252341): timing attacks in RSA operations
- CVE-2025-59438 (boo#1252454): padding-oracle attack via timing of cipher error reporting
- CVE-2026-25833: PSA RNG state duplicated across fork()
- CVE-2026-25834: TLS 1.3 HelloRetryRequest man-in-the-middle session-resumption downgrade
- CVE-2026-25835: RNG state duplicated when application/VM state is cloned
- Record
openSUSE-SU-2026:21144-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:21864-1 No score
Security update for mbedtls-2
This update for mbedtls-2 fixes the following issues:
Changes in mbedtls-2:
- CVE-2025-52496: race condition in AESNI support detection, AES key disclosure / GCM forgery in multithreaded programs (boo#1245810)
- CVE-2025-59438: padding oracle through timing of cipher error reporting (boo#1252454)
- Record
openSUSE-SU-2026:21864-1- Updated
- 2026-11-02
OSVUSN-8123-1 No score
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 the behavior of a function. Application code relying on the documented behavior might be affected. A remote attacker could possibly use this issue to execute arbitrary code. (CVE-2025-47917)
Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled crafted input. A remote attacker could possibly use this issue to crash the program, resulting in a denial of service. (CVE-2025-48965)
It was discovered that Mbed TLS incorrectly handled a race condition. An attacker could possibly use this issue to extract AES keys. (CVE-2025-52496)
Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled certain invalid input. A remote attacker could possibly use this issue to crash the program, resulting in a denial of service. (CVE-2025-52497)
- Record
USN-8123-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mbedtlsAlpine:v3.20 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtlsAlpine:v3.21 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtlsAlpine:v3.22 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtlsAlpine:v3.23 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtlsAlpine:v3.24 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtls3Alpine:v3.24 |
before 3.6.4-r0 | 3.6.4-r0 |
mbedtlsDebian:12 |
All versions, plus listed versions 2.28.3-12.28.4-12.28.5-12.28.6-12.28.7-1 Show 17 moreShow less2.28.7-1.12.28.7-1.1~exp12.28.8-13.6.0-13.6.0-23.6.0-33.6.2-13.6.2-23.6.2-33.6.3-13.6.4-13.6.4-23.6.5-0.13.6.5-0.1~deb13u13.6.6-0.13.6.7-23.6.7-3 |
None known |
mbedtlsDebian:13 |
before 3.6.4-1 | 3.6.4-1 |
mbedtlsDebian:14 |
before 3.6.4-1 | 3.6.4-1 |
mbedtlsDebian:11 From an advisory covering 4 CVEs |
before 2.16.9-0.1+deb11u2, plus listed versions 2.16.9-0.12.16.9-0.1+deb11u1 |
2.16.9-0.1+deb11u2 |
Show 16 moreShow less
| Package | Affected | Fixed |
|---|---|---|
MbedTLS_jllJulia |
before 2.28.1010+0 | 2.28.1010+0 |
mbedtlsRoot:Debian:12 |
before 2.28.3-1.root.io.14 | 2.28.3-1.root.io.142.28.3-1.root.io.92.28.3-1.root.io.72.28.3-1.root.io.102.28.3-1.root.io.152.28.3-1.root.io.162.28.3-1.root.io.82.28.3-1.root.io.112.28.3-1.root.io.122.28.3-1.root.io.132.28.3-1.aikido.17 |
rootio-mbedtlsRoot:Debian:12 |
before 2.28.3-1.root.io.14 | 2.28.3-1.root.io.142.28.3-1.root.io.92.28.3-1.root.io.72.28.3-1.root.io.102.28.3-1.root.io.152.28.3-1.root.io.162.28.3-1.root.io.82.28.3-1.root.io.112.28.3-1.root.io.122.28.3-1.root.io.132.28.3-1.aikido.17 |
mbedtlsUbuntu:16.04:LTS |
All versions, plus listed versions 2.1.2-12.2.0-12.2.1-12.2.1-22.2.1-2ubuntu0.12.2.1-2ubuntu0.22.2.1-2ubuntu0.3 |
None known |
mbedtlsUbuntu:Pro:18.04:LTS |
before 2.8.0-1ubuntu0.1~esm1, plus listed versions 2.5.1-1ubuntu12.6.0-12.7.0-22.8.0-1 |
2.8.0-1ubuntu0.1~esm1 |
mbedtlsUbuntu:Pro:20.04:LTS |
before 2.16.4-1ubuntu2+esm1, plus listed versions 2.16.2-12.16.3-12.16.4-1ubuntu2 |
2.16.4-1ubuntu2+esm1 |
mbedtlsUbuntu:Pro:22.04:LTS |
before 2.28.0-1ubuntu0.1~esm1, plus listed versions 2.16.9-0.1ubuntu12.16.11-0.1ubuntu12.16.11-0.32.28.0-12.28.0-1build1 |
2.28.0-1ubuntu0.1~esm1 |
mbedtlsUbuntu:Pro:24.04:LTS |
before 2.28.8-1ubuntu0.1~esm1, plus listed versions 2.28.3-12.28.6-1ubuntu12.28.7-1ubuntu12.28.7-1.1ubuntu12.28.8-1 |
2.28.8-1ubuntu0.1~esm1 |
mbedtlsUbuntu:25.10 |
All versions, plus listed versions 3.6.2-3ubuntu1 |
None known |
mbedtlsUbuntu:Pro:18.04:LTS From an advisory covering 7 CVEs |
before 2.8.0-1ubuntu0.1~esm1, plus listed versions 2.5.1-1ubuntu12.6.0-12.7.0-22.8.0-1 |
2.8.0-1ubuntu0.1~esm1 |
mbedtlsUbuntu:Pro:20.04:LTS From an advisory covering 7 CVEs |
before 2.16.4-1ubuntu2+esm1, plus listed versions 2.16.2-12.16.3-12.16.4-1ubuntu2 |
2.16.4-1ubuntu2+esm1 |
mbedtlsUbuntu:Pro:22.04:LTS From an advisory covering 7 CVEs |
before 2.28.0-1ubuntu0.1~esm1, plus listed versions 2.16.9-0.1ubuntu12.16.11-0.1ubuntu12.16.11-0.32.28.0-12.28.0-1build1 |
2.28.0-1ubuntu0.1~esm1 |
mbedtlsUbuntu:Pro:24.04:LTS From an advisory covering 7 CVEs |
before 2.28.8-1ubuntu0.1~esm1, plus listed versions 2.28.3-12.28.6-1ubuntu12.28.7-1ubuntu12.28.7-1.1ubuntu12.28.8-1 |
2.28.8-1ubuntu0.1~esm1 |
mbedtls-2openSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 2.28.10-5.1 | 2.28.10-5.1 |
mbedtlsopenSUSE:Leap 16.0 From an advisory covering 15 CVEs |
before 3.6.6-bp160.1.1 | 3.6.6-bp160.1.1 |
mbedtls-2openSUSE:Leap 16.0 From an advisory covering 2 CVEs |
before 2.28.10-bp160.2.1 | 2.28.10-bp160.2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-52496 is a high vulnerability (CVSS 7.8) in Arm Mbed Tls, published July 4, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in mbedtls 3.6.4-r0.
References
github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-1.md
lists.debian.org/debian-lts-announce/2025/08/msg00013.html
nvd.nist.gov/vuln/detail/CVE-2025-52496
github.com/advisories/GHSA-qc26-g9mm-wmmf
security.alpinelinux.org/vuln/CVE-2025-52496
github.com/CVEProject/cvelistV5/tree/main/cves/2025/52xxx/CVE-2025-52496.json
Show 37 moreShow less
security-tracker.debian.org/tracker/CVE-2025-52496
ubuntu.com/security/CVE-2025-52496
cve.org/CVERecord?id=CVE-2025-52496
ubuntu.com/security/notices/USN-8123-1
ubuntu.com/security/CVE-2021-44732
ubuntu.com/security/CVE-2024-23775
ubuntu.com/security/CVE-2025-27810
ubuntu.com/security/CVE-2025-47917
ubuntu.com/security/CVE-2025-48965
ubuntu.com/security/CVE-2025-52497
suse.com/security/cve/CVE-2025-52496
suse.com/security/cve/CVE-2025-59438
bugzilla.suse.com/1231708
bugzilla.suse.com/1240051
bugzilla.suse.com/1240052
bugzilla.suse.com/1245808
bugzilla.suse.com/1245809
bugzilla.suse.com/1245810
bugzilla.suse.com/1245811
bugzilla.suse.com/1246783
bugzilla.suse.com/1246784
bugzilla.suse.com/1246973
bugzilla.suse.com/1252341
bugzilla.suse.com/1252454
suse.com/security/cve/CVE-2024-49195
suse.com/security/cve/CVE-2025-27809
suse.com/security/cve/CVE-2025-27810
suse.com/security/cve/CVE-2025-47917
suse.com/security/cve/CVE-2025-48965
suse.com/security/cve/CVE-2025-49087
suse.com/security/cve/CVE-2025-49600
suse.com/security/cve/CVE-2025-49601
suse.com/security/cve/CVE-2025-52497
suse.com/security/cve/CVE-2025-54764
suse.com/security/cve/CVE-2026-25833
suse.com/security/cve/CVE-2026-25834
suse.com/security/cve/CVE-2026-25835