CVE-2026-39827

Summary

golang.org/x/crypto/ssh: Invoking memory leak when rejecting channels can lead to DoS

Severity

medium

CVSS

6.5

EPSS

0.3% (p20)

CWE

CWE-924

Also known as

GHSA-qpw4-5x99-6vjp, GO-2026-5016

Published

2026-06-25

Updated

2026-06-25

Advisory details

An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.

References

• https://github.com/advisories/GHSA-qpw4-5x99-6vjp
• https://nvd.nist.gov/vuln/detail/CVE-2026-39827
• https://go.dev/cl/781320
• https://go.dev/issue/35127
• https://groups.google.com/g/golang-announce/c/a082jnz-LvI
• https://pkg.go.dev/vuln/GO-2026-5016

Related advisories

• 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-2026-39835 — medium · Go/golang.org/x/crypto/ssh
• CVE-2026-39828 — medium · Go/golang.org/x/crypto/ssh

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