Vulnerability in Sigstore Sigstore-Go
CVE-2026-49834
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (7.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Sigstore Sigstore-Go — versions < 1.2.0
Weakness classification (CWE)
References
- github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6 (Vendor Advisory)
- github.com/sigstore/sigstore-go/pull/633 (Patch, Issue Tracking)
- github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207 (Patch)
- github.com/sigstore/sigstore-go/releases/tag/v1.2.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-49834?
- CVE-2026-49834 is a medium-severity vulnerability in Sigstore Sigstore-Go, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.9/10. Published 2026-07-17.
- How severe is CVE-2026-49834?
- Medium severity. CVSS v3 base score is 5.9 out of 10.