Low severity · published Sep 14, 2026
CVE-2026-25832
In Mbed TLS 3.6.x before 3.6.7 and 4.1.x before 4.1.2, the TLS 1.3 client accepts HelloRetryRequest selecting an unadvertised group
3.7
CVSS
0.3%
EPSS
No
On KEV
Description
In Mbed TLS 3.6.x before 3.6.7 and 4.1.x before 4.1.2, the TLS 1.3 client accepts HelloRetryRequest selecting an unadvertised group.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MT
Mbed TLS · TrustedFirmware
3.5.0 before 3.6.7; 4.0.0 before 4.1.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25832
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25832
mbed-tls.readthedocs.io
https://mbed-tls.readthedocs.io/en/latest/security-advisories/
mbed-tls.readthedocs.io
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-07-tls13-hrr-unadvertised-group/
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