CVE-2026-39835 PUBLISHED

Invoking server panic during CheckHostKey/Authenticate in golang.org/x/crypto/ssh

Assigner: Go
Reserved: 07.04.2026 Published: 22.05.2026 Updated: 22.05.2026

SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.

Product Status

Vendor golang.org/x/crypto
Product golang.org/x/crypto/ssh
Versions Default: unaffected
  • affected from 0 to 0.52.0 (excl.)

Credits

  • NCC Group Cryptography Services, sponsored by Teleport

References

Problem Types

  • CWE-476: NULL Pointer Dereference