Vulnerability record · CVE-2026-49834 · published 17 July 2026

CVE-2026-49834: Sigstore-go improper verification of cryptographic signature vulnerability

Sigstore · Sigstore Go

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.

7.5 CVSS 3.1 High EPSS 0.18% · top 93.1% CWE-347 · Improper verification of cryptographic signature

7.5CVSS 3.1 base score

0.18%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

4References

30 Jul 2026Last modified by NVD

Description

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Sigstore Go Sigstore

References

Link	Tags
https://github.com/sigstore/sigstore-go/commit/dbb07e62623edd5b175fb9dd5a41dcb85a159207	Patch
https://github.com/sigstore/sigstore-go/pull/633	Issue TrackingPatch
https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0	ProductRelease Notes
https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6	Vendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-49834), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.