CVE-2026-123609rustls rustls
NVD
Vulnerability Summary
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 v4.0 Base Metrics — Score 4.1 (MEDIUM)
CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NAttack VectorLocal
Attack ComplexityHigh
Attack RequirementsPresent
Privileges RequiredHigh
User InteractionPassive
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)None
Availability (Vulnerable System)None
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 4.0)
CVSS v3.1 Base Metrics — Score 4.0 (MEDIUM)
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:NAttack VectorLocal
Attack ComplexityHigh
Privileges RequiredHigh
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityNone
Affected & Patched Versions
- rustls rustls < 0.23.46
- rustls rustls >= 0.24.0-dev.1 and < 0.24.0-dev.2
- rustls rustls 0.23.46
- rustls rustls 0.24.0-dev.2
What to do
Fix it during your normal patch cycle. No exploitation is confirmed yet.
- Check whether you run rustls rustls and which version.
- Update to a patched version listed above, then confirm the new version.
Timeline
- Nov 8, 2026Published
- Nov 10, 2026Record last modified
Score, severity and exploitation changes are tracked from the day Watchtower started logging them.
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Data last checked: Nov 14, 2026 02:13 UTC