CVE-2026-34873
critical
CVSS v3
9.1
CVSS v4 NEW
—
VIR risk
9.1
Description
An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.
Predictions
Exploit likelihood
94%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 3.6.6-0.1 |
| forky | Fixed | 3.6.6-0.1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
References
- https://www.suse.com/security/cve/CVE-2026-34873.html
- https://security-tracker.debian.org/tracker/CVE-2026-34873
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/
- https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-client-impersonation-while-resuming-tls13-session/
CWEs
CWE-287
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.