medium5.9
CVE-2026-49834
sigstore-go has a multi-log threshold bypass via single compromised log
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/sigstore/sigstore-go | <= 1.1.4 | 1.2.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Sigstore | Sigstore-Go | before 1.2.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-9vcr-p3rj-q5q6
- https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6
- https://nvd.nist.gov/vuln/detail/CVE-2026-49834
- https://github.com/sigstore/sigstore-go/pull/633
- https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207
- https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0