CVE-2026-25832

EUVD-2026-77305
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mitreCNA
3.7 LOW
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 20.63%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
trustedfirmwarembed_tls
3.5.0 ≤
𝑥
< 3.6.7
CNA
trustedfirmwarembed_tls
4.0.0 ≤
𝑥
< 4.1.2
CNA
Debian logo
Debian Releases
Debian Product
Codename
mbedtls
bookworm
vulnerable
forky
3.6.7-3
fixed
sid
3.6.7-3
fixed
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
mbedtls
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
stonking
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://mbed-tls.readthedocs.io/en/latest/security-advisories/
https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-07-tls13-hrr-unadvertised-group/