Vulnerability Description
During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the initial handshake, or cause a server to resume a session with a client that it would not have resumed with during the initial handshake.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Golang | Go | < 1.24.13 |
Related Weaknesses (CWE)
References
- https://go.dev/cl/737700Patch
- https://go.dev/issue/77217ExploitIssue Tracking
- https://groups.google.com/g/golang-announce/c/K09ubi9FQFkMailing ListThird Party Advisory
- https://pkg.go.dev/vuln/GO-2026-4337Vendor Advisory
FAQ
What is CVE-2025-68121?
CVE-2025-68121 is a vulnerability with a CVSS score of 10.0 (CRITICAL). During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed...
How severe is CVE-2025-68121?
CVE-2025-68121 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2025-68121?
Check the references section above for vendor advisories and patch information. Affected products include: Golang Go.