CVE-2026-39835

Summary

golang.org/x/crypto/ssh is vulnerable to invoking server panic during CheckHostKey/Authenticate flow

Severity

medium

CVSS

5.3

EPSS

0.5% (p41)

CWE

CWE-295

Also known as

GHSA-78mq-xcr3-xm33, GO-2026-5015

Published

2026-06-25

Updated

2026-06-25

Advisory details

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.

References

• https://github.com/advisories/GHSA-78mq-xcr3-xm33
• https://nvd.nist.gov/vuln/detail/CVE-2026-39835
• https://go.dev/cl/781660
• https://go.dev/issue/79563
• https://groups.google.com/g/golang-announce/c/a082jnz-LvI
• https://pkg.go.dev/vuln/GO-2026-5015

Related advisories

• CVE-2026-39828 — medium · Go/golang.org/x/crypto/ssh
• CVE-2026-46595 — critical · Go/golang.org/x/crypto/ssh
• CVE-2026-39834 — critical · Go/golang.org/x/crypto/ssh
• CVE-2026-39831 — critical · Go/golang.org/x/crypto/ssh
• CVE-2026-39830 — critical · Go/golang.org/x/crypto/ssh
• CVE-2026-39829 — high · Go/golang.org/x/crypto/ssh
• CVE-2026-46597 — high · Go/golang.org/x/crypto/ssh
• CVE-2026-39827 — medium · Go/golang.org/x/crypto/ssh

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