CVE-2026-49834 MEDIUM

CVE-2026-49834: sigstore-go: Multi-log threshold bypass via single compromised log

Vendor Sigstore

Product sigstore-go

Weakness CWE-347

Published July 17, 2026

Last update July 17, 2026

View on NVD All CVEs

CVSS base score

5.9/10

Attack vector Network

Attack complexity High

Privileges required None

User interaction None

Confidentiality None

Integrity High

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 17, 2026 CVE published

July 17, 2026 Record updated

External resources

03References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2026-49834 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/347.html AskarLabs — CWE-347 write-up Improper Verification of Cryptographic Signature

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04Related CVE

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