CVE-2026-27138 PUBLISHED

Panic in name constraint checking for malformed certificates in crypto/x509

Assigner: Go
Reserved: 17.02.2026 Published: 06.03.2026 Updated: 06.03.2026

Certificate verification can panic when a certificate in the chain has an empty DNS name and another certificate in the chain has excluded name constraints. This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.

Product Status

Vendor Go standard library
Product crypto/x509
Versions Default: unaffected
  • affected from 0 to 1.26.1 (excl.)

Credits

  • Jakub Ciolek

References

Problem Types

  • CWE-1285: Improper Validation of Specified Index, Position, or Offset in Input