crypto/tls: TLS Session Key Mismanagement in Config.Clone and GetConfigForClient

Exploitable under specific conditions

This CVE can affect KrakenD under specific conditions. Review the affected versions below and upgrade if your deployment is exposed.

The Config.Clone variant can affect any deployment that clones its TLS configuration at startup, which may occur in multi-listener setups. The GetConfigForClient variant only affects deployments using a custom per-client TLS callback. Upgrading is recommended regardless of configuration.

Component

Go standard library (crypto/tls)

Disclosed

Feb 10, 2026

CVSS Score

5.9

Description

Two related flaws in Go’s crypto/tls package affect session ticket key handling:

tls.Config.Clone leaks session ticket keys and ignores full certificate chain expiration when the original Config has custom session ticket keys set.
tls.Config.GetConfigForClient does not correctly propagate session ticket keys to the returned Config when authentication parameters are modified.

Both issues can result in authentication state inconsistency or unintended session ticket exposure.

Version summary

Community Edition

2.13.0

addresses this CVE

Affected CE versions

>= 2.0, < 2.13.0

Enterprise Edition

2.12.4

addresses this CVE

Affected EE versions

>= 2.0, < 2.12.4

Upgrade to the addressed version or later to remediate this vulnerability.

References

View CVE-2025-68121 on Go Issue Tracker (GetConfigForClient) View CVE-2025-68121 on Go Issue Tracker (Config.Clone)

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