CVE-2026-123609 — MEDIUM (4.0)

Vulnerability Description

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ClientSessionStore implementations that log Tls12ClientSessionValue or Tls13ClientSessionValue can leak TLS 1.2 master secrets or TLS 1.3 resumption PSKs to log readers.

CVSS Score

4.0

MEDIUM

CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-212

References

FAQ

What is CVE-2026-123609?

CVE-2026-123609 is a vulnerability with a CVSS score of 4.0 (MEDIUM). Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ...

How severe is CVE-2026-123609?

CVE-2026-123609 has been rated MEDIUM with a CVSS base score of 4.0/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-123609?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.