CVE-2026-123609 PUBLISHED

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 Secret Exposure via Debug

Assigner: VulnCheck
Reserved: 06.11.2026 Published: 08.11.2026 Updated: 08.11.2026

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 Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 4.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	High
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N
CVSS Score: 4

Attack Vector	Local	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	High	Integrity Impact	None
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	rustls
Product	rustls
Versions	Default: unaffected affected from 0 to 0.23.46 (excl.) Version 0.23.46 is unaffected affected from 0.24.0-dev.1 to 0.24.0-dev.2 (excl.) Version 0.24.0-dev.2 is unaffected

References

Problem Types

Improper Removal of Sensitive Information Before Storage or Transfer CWE