CVE-2026-49834 — MEDIUM (5.9)

Vulnerability Description

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.

CVSS Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Sigstore	Sigstore-Go	< 1.2.0

Related Weaknesses (CWE)

CWE-347

References

https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85Patch
https://github.com/sigstore/sigstore-go/pull/633Issue TrackingPatch
https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0ProductRelease Notes
https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6Vendor Advisory

FAQ

What is CVE-2026-49834?

CVE-2026-49834 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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...

How severe is CVE-2026-49834?

CVE-2026-49834 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-49834?

Check the references section above for vendor advisories and patch information. Affected products include: Sigstore Sigstore-Go.