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.
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-07-tls13-hrr-unadvertised-group/
https://mbed-tls.readthedocs.io/en/latest/security-advisories/
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-77305
Source: Mitre, NVD
Published: 2026-09-14
Updated: 2026-09-22
Base Score: 2.6
Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:P/A:N
Severity: Low
Base Score: 3.7
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS: 0.00218