CVE-2026-49834: Sigstore Sigstore-Go

High severity, CVSS 7.5. EPSS: 0.2% chance of exploitation in the next 30 days.

sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.0, a verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) counts verified witnesses per entry or per validation path rather than per log authority, allowing a single compromised transparency log or CT log to satisfy multi-log threshold requirements and defeat the multi-log policy. This issue is fixed in version 1.2.0.

Affected products

• Sigstore Sigstore-Go: before 1.2.0 (fixed in 1.2.0)

Published 2026-07-17. Last modified 2026-07-30.