CVE-2026-42508: Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts

Published May 22, 2026
·
Updated

Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts

Other sources

Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.

MITRE

Affected Software

8 affected componentsFixes available
go/golang.org/x/crypto/ssh/knownhosts
Microsoft azl3 telegraf 1.31.0-19
Microsoft azl3 packer 1.9.5-13
debian/golang-go.crypto<=1:0.0~git20201221.eec23a3-1, <=1:0.4.0-1, <=1:0.25.0-1
1:0.53.0-1
Golang Crypto Go<0.52.0
go/golang.org/x/crypto/ssh/knownhosts<0.52.0
0.52.0
IBM Db2 Genius Hub<=1.1, 1.1.1, 1.1.2
IBM Agentics<=1.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/golang-go.crypto to a version that resolves this vulnerability.

    Fixed in 1:0.53.0-1
  2. Upgrade

    Upgrade go/golang.org/x/crypto/ssh/knownhosts to a version that resolves this vulnerability.

    Fixed in 0.52.0

Event History

May 22, 2026
CVE Published
via MITRE·02:31 AM
Data Sourced
via MITRE·02:31 AM
DescriptionWeakness
Data Sourced
via Red Hat·04:02 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:16 AM
DescriptionSeverityWeaknessAffected Software
May 27, 2026
Data Sourced
via Microsoft·08:18 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:18 AM
Affected Software
Updated
via Microsoft·08:18 AM
DescriptionSeverity
Jun 19, 2026
Data Sourced
via Ubuntu·08:48 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·08:49 PM
Description
Data Sourced
via Debian·08:49 PM
DescriptionAffected Software
Jun 25, 2026
Advisory Published
via GitHub·10:22 PM
Data Sourced
via GitHub·10:22 PM
DescriptionSeverityWeaknessAffected Software
Jul 13, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-42508?

CVE-2026-42508 has a risk rating of 55, indicating it is a moderate vulnerability.

2

How do I fix CVE-2026-42508?

To remediate CVE-2026-42508, ensure that both the 'key' and 'key.SignatureKey' are properly checked for revocation in your implementation of golang.org/x/crypto/ssh/knownhosts.

3

What software is affected by CVE-2026-42508?

CVE-2026-42508 affects the golang.org/x/crypto/ssh/knownhosts module.

4

When was CVE-2026-42508 published?

CVE-2026-42508 was published on May 22, 2026.

5

What does CVE-2026-42508 involve?

CVE-2026-42508 involves an authentication bypass due to improper checking of a revoked 'SignatureKey' in the knownhosts module.

Contact

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