No exploitation reportedFix available

CVE-2026-42508

Q: Is CVE-2026-42508 actively exploited?

Active exploitation of CVE-2026-42508 has not been confirmed. Its EPSS score was 0.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-42508?

CVE-2026-42508 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

No exploitation reported by the sources we read.

Published2026-05-22
Fixed in0.52.0
WeaknessCWE-295

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2026-05-2204:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-42508?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-42508?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Golang crypto

Branch	Affected	Fixed in	Source
0.52	< 0.52.0	0.52.0	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

aardvark-dnsAlmaLinux:8all versions · fixed in 2:1.10.1-2.module_el8.10.0+3901+4b80ecd7
aardvark-dnsAlmaLinux:8all versions · fixed in 2:1.10.1-2.module_el8.10.0+3909+6e1c1eb7
aardvark-dnsAlmaLinux:8all versions · fixed in 2:1.10.1-2.module_el8.10.0+4047+545787c4
aardvark-dnsAlmaLinux:8all versions · fixed in 2:1.10.1-2.module_el8.10.0+4089+ce72bbbe
buildahAlmaLinux:8all versions · fixed in 2:1.33.14-4.module_el8.10.0+4213+0493256band 1 other package
cockpit-podmanAlmaLinux:8all versions · fixed in 84.1-1.module_el8.10.0+4102+6c76e544
conmonAlmaLinux:8all versions · fixed in 3:2.1.10-1.module_el8.10.0+4068+0e21408f
conmonAlmaLinux:8all versions · fixed in 3:2.1.10-1.module_el8.10.0+3970+8445edf6

53 more package ranges on OSV.dev

Vendor advisories

CVE-2026-42508 Red Hat Product Security1,107 products fixed · 31 known affected
golang.org/x/crypto/ssh/knownhosts: golang: golang.org/x/crypto/ssh/knownhosts: Revocation bypass via unchecked SignatureKey
external-secrets-operator/external-secrets-rhel9 as a component of External Secrets Operator for Red Hat OpenShift · openshift-pipelines/pipelines-chains-controller-rhel9 as a component of OpenShift Pipelines · openshift-pipelines/pipelines-pipelines-as-code-controller-rhel9 as a component of OpenShift Pipelines · +28 more
RHSA-2026:82322 Red Hat Product Security4 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.17.2
RHSA-2026:82304 Red Hat Product Security8 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.17.2
RHSA-2026:73987 Red Hat Product Security6 products fixed
Red Hat Security Advisory: RHOAI 3.3.7 - Red Hat OpenShift AI
RHSA-2026:70870 Red Hat Product Security4 products fixed
Red Hat Security Advisory: Logging for Red Hat OpenShift - 6.5.3
RHSA-2026:70267 Red Hat Product Security4 products fixed
Red Hat Security Advisory: Red Hat Quay 3.14.9

48 more advisories

Full record on NVD

Fix

Update Golang crypto to 0.52.0
Vendor fix Red Hat Product Security RHSA-2026:82322 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. The steps to apply the upgraded images are different depending on the installation plan approval policy you used when installing the cert-manager Operator for Red Hat OpenShift. - If t…
Vendor fix Red Hat Product Security RHSA-2026:73987 · 6 productsFor Red Hat OpenShift AI 3.3.7 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
Vendor fix Red Hat Product Security RHSA-2026:70870 · 4 productsFor OpenShift Container Platform 4.21 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/relea…
Vendor fix Red Hat Product Security RHSA-2026:70267 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11458
Vendor fix Red Hat Product Security RHSA-2026:67450 · 38 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Vendor fix Red Hat Product Security RHSA-2026:66521 · 4 productsFor OpenShift Container Platform 4.22 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.22/html/relea…

Advisories and patches

pkg.go.devVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2026-05-22
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.19.12026-05-22
CNACVSS 3.17.4read 2026-10-23
CNAweakness (CWE)CWE-295read 2026-10-23
NVDweakness (CWE)CWE-295read 2026-10-23
FIRST EPSSEPSS score0.7 %2026-10-22
OSVaffected packages—
Microsoft MSRCadvisory—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Published: 2026-05-22
Last Modified: 2026-09-15
NVD status: Modified
MSRC Title: Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts

Frequently asked questions

What is CVE-2026-42508?

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.

Is CVE-2026-42508 actively exploited?

Active exploitation of CVE-2026-42508 has not been confirmed. Its EPSS score was 0.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-42508?

CVE-2026-42508 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

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