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.
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39835.json
https://pkg.go.dev/vuln/GO-2026-5015
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
https://bugzilla.redhat.com/show_bug.cgi?id=2480680
https://access.redhat.com/security/cve/CVE-2026-39835
https://access.redhat.com/errata/RHSA-2026:38504
https://access.redhat.com/errata/RHSA-2026:37410
https://access.redhat.com/errata/RHSA-2026:37387
https://access.redhat.com/errata/RHSA-2026:37296
https://access.redhat.com/errata/RHSA-2026:37286
https://access.redhat.com/errata/RHSA-2026:37272
https://access.redhat.com/errata/RHSA-2026:37271
https://access.redhat.com/errata/RHSA-2026:37268
https://access.redhat.com/errata/RHSA-2026:37123
https://access.redhat.com/errata/RHSA-2026:37072
https://access.redhat.com/errata/RHSA-2026:36797
https://access.redhat.com/errata/RHSA-2026:36796
https://access.redhat.com/errata/RHSA-2026:36651
https://access.redhat.com/errata/RHSA-2026:36648
https://access.redhat.com/errata/RHSA-2026:36625
https://access.redhat.com/errata/RHSA-2026:36319
https://access.redhat.com/errata/RHSA-2026:36207
https://access.redhat.com/errata/RHSA-2026:36199