Medium severity · published May 22, 2026
CVE-2026-39835
Invoking server panic during CheckHostKey/Authenticate in golang.org/x/crypto/ssh
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GO
golang.org/x/crypto/ssh · golang.org/x/crypto
before 0.52.0 · source: vendor
CR
Crypto · Golang
before 0.52.0 · source: NVD
AI
Assisted Installer for Red Hat OpenShift Container Platform 2 · Red Hat
All versions, or not specified · source: CISA
CC
Confidential Compute Attestation · Red Hat
All versions, or not specified · source: CISA
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift 6.6 · Red Hat
All versions, or not specified · source: CISA
ME
Multicluster Engine for Kubernetes · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.3 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.4 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.5 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.6 · Red Hat
All versions, or not specified · source: CISA
OP
OpenShift Pipelines · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39835
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-39835
Issue Tracking
https://go.dev/cl/781660
Issue Tracking
https://go.dev/issue/79563
Mailing List
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
Vendor Advisory
https://pkg.go.dev/vuln/GO-2026-5015
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26546
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26547
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