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CVE-2026-39830

Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh

Published: May 22, 2026Updated: Jun 2, 2026 Sources: CVE List NVDCWE-119
NVD MITRE
9.1CVSSCRITICAL
EPSS Score
0.3%
Top 77.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-119

Affected Products

golang.org/x/crypto/sshgolang.org/x/crypto
Library
OSS Libraries / go
cryptogolangOSS Libraries
golang.org/x/cryptooss-projectOSS Librariesaka x/crypto, golang x crypto
golangoss-projectUSOSS Libraries

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://go.dev/issue/79564
go.dev
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
groups.google.com
https://go.dev/cl/781640
go.dev
and 2 more references View all →

Timeline

Published
May 22, 2026
Last Updated
Jun 2, 2026

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