What’s Vulnerable › Vulnerabilities

CVE-2026-54787: sigstore-go fails to check signature timestamps against a signing key's validity period

• Severity: low (CVSS 3.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-31 · updated 2026-10-23
• Weakness: CWE-324

Description

sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.

Affected products

• sigstore-go: before 1.2.1

References

• https://github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f
• https://github.com/sigstore/sigstore-go/pull/642
• https://github.com/sigstore/sigstore-go/releases/tag/v1.2.1
• https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm
• https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm

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