CyberSecBulletin
CVE-2026-39828NVD status: Modified

golang.org/x/crypto/ssh: Improper Certificate Validation

Published Updated By the CyberSecBulletin desk

CVE-2026-39828 is a high-severity improper certificate validation vulnerability in golang.org/x/crypto/ssh from Golang.org/x/crypto, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 0.52.0 as the first without the flaw, so updating golang.org/x/crypto/ssh to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update golang.org/x/crypto/ssh to 0.52.0 or a later version.
  2. Read the advisory on pkg.go.dev for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Golang.org/x/cryptogolang.org/x/crypto/sshbefore 0.52.00.52.0
Red HatCryostat 4 on RHEL 9Not specified in the recordNot stated
Red HatRHEM 1.0 for RHEL 9Not specified in the recordNot stated
Red HatRHEM 1.1 for RHEL 10Not specified in the recordNot stated
Red HatRHEM 1.1 for RHEL 9Not specified in the recordNot stated
Red HatCert Manager support for Red Hat OpenShift release 1.19Not specified in the recordNot stated
Red HatDevWorkspace Operator 0.42Not specified in the recordNot stated
Red HatLogging Subsystem for Red Hat OpenShift 6.6Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.1Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.11Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.6Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.8Not specified in the recordNot stated
Red HatOpenShift API for Data Protection 1.3Not specified in the recordNot stated
Red HatOpenShift API for Data Protection 1.4Not specified in the recordNot stated
Red HatOpenShift API for Data Protection 1.5Not specified in the recordNot stated
Red HatOpenShift API for Data Protection 1.6Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.15Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.16Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Security 4.9Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Security for Kubernetes 4.10Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Security for Kubernetes 4.11Not specified in the recordNot stated
Red HatRed Hat Edge Manager 1.0Not specified in the recordNot stated
Red HatRed Hat Edge Manager 1.1Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 3.4Not specified in the recordNot stated
Red HatRed Hat OpenShift Builds 1.7.3Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 35 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.16.3MediumCISA (ADP)
CVSS 3.18.8HighCNA

Official description

When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in golang.org/x/crypto/ssh

All golang.org/x/crypto/ssh vulnerabilities

Recent Improper Certificate Validation vulnerabilities

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