TI-2026-19440 Aliases CVE-2026-24122 GHSA-wfqv-66vq-46rm

Cosign Certificate Chain Expiry Validation Issue Allows Issuing Certificate Expiry to Be Overlooked

LOW 17CWE-295Published 2026-02-19 · Updated 2026-02-20

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Impact type: Spoofing
Confidentiality · integrity · availability: None · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-295.

Summary

Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00215 12th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed cosign (sigstore): 3.0.5github.com/sigstore/cosign (Go): 3.0.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
sigstore	cosign	before 3.0.5	3.0.5	Patch available	CNA
—	github.com/sigstore/cosign (Go)	before 3.0.5	3.0.5	Patch available	GHSA-wfqv-66vq-46rm

cosign Vendorsigstore Affected before 3.0.5 Fixed in 3.0.5 Patch available CNA
github.com/sigstore/cosign (Go) Vendor— Affected before 3.0.5 Fixed in 3.0.5 Patch available GHSA-wfqv-66vq-46rm

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:sigstore:cosign::::::::	before 3.0.5	Vulnerable	sigstore

cpe:2.3:a:sigstore:cosign:*:*:*:*:*:*:*:* Versions before 3.0.5 Vulnerable ·sigstore

Remediation

Fix · CNA cosign (sigstore) Fixed in 3.0.5
Fix · GHSA-wfqv-66vq-46rm github.com/sigstore/cosign (Go) Fixed in 3.0.5 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Not affected: 12 products

External Secrets Operator for Red Hat OpenShift
OpenShift Pipelines
OpenShift Serverless
Red Hat Advanced Cluster Management for Kubernetes 2
Red Hat Advanced Cluster Security 4
Red Hat OpenShift AI (RHOAI)
Red Hat OpenShift Container Platform 4
Red Hat Satellite 6
Red Hat Trusted Artifact Signer
Security Profiles Operator
Zero Trust Workload Identity Manager
Zero Trust Workload Identity Manager - Tech Preview

Timeline

2026-10-02 Threatist record created from CVE-2026-24122
2026-10-03 Alias added: GHSA-wfqv-66vq-46rm

References

Other 2

TI-2022-16356 False positive signature verification in cosign CVSS 3.1CRITICAL 9.8
TI-2024-19670 Cosign vulnerable to machine-wide denial of service via malicious artifacts CVSS 3.1HIGH 7.5
TI-2024-19669 Cosign vulnerable to system-wide denial of service via malicious attachments CVSS 3.1MEDIUM 5.9
TI-2022-16479 Vulnerabilities with blob verification in sigstore cosign CVSS 3.1MEDIUM 5.5
TI-2023-25220 Possible endless data attack from attacker-controlled registry in cosign CVSS 3.1MEDIUM 5.3
TI-2026-28380 Cosign's verify-blob-attestation reports false positive when payload parsing fails CVSS 3.1MEDIUM 5.3

See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences