GHSA-9vcr-p3rj-q5q6

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Source
https://github.com/advisories/GHSA-9vcr-p3rj-q5q6
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-9vcr-p3rj-q5q6/GHSA-9vcr-p3rj-q5q6.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-9vcr-p3rj-q5q6
Aliases
  • CVE-2026-49834
Downstream
Related
Published
2026-07-09T23:20:30Z
Modified
2026-07-10T15:44:38.499797591Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
sigstore-go has a multi-log threshold bypass via single compromised log
Details

Impact

What kind of vulnerability is it? Who is impacted?

A verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) expected defense-in-depth against the compromise of a single log instance. However, threshold counting counted verified witnesses per-entry or per-validation-path rather than per-log-authority.

As a result, a single compromised transparency log could forge multiple entries with different indices, and a single compromised CT log could verify multiple times (either across multiple certificate chains or via multiple embedded SCTs), fully satisfying the multi-log threshold requirements and defeating the multi-log policy.

Note that this does not affect Cosign, as Cosign sets a threshold of 1.

Patches

Has the problem been patched? What versions should users upgrade to?

Upgrade to v1.1.5.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

There is no workaround, beyond relying on trusted logs.

Database specific 
{
    "github_reviewed_at": "2026-07-09T23:20:30Z",
    "nvd_published_at": null,
    "cwe_ids": [
        "CWE-345"
    ],
    "severity": "MODERATE",
    "github_reviewed": true
}
References

Affected packages

Go / github.com/sigstore/sigstore-go

Package

Name
github.com/sigstore/sigstore-go
View open source insights on deps.dev
Purl
pkg:golang/github.com/sigstore/sigstore-go

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.2.0

Database specific

last_known_affected_version_range 
"<= 1.1.4"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-9vcr-p3rj-q5q6/GHSA-9vcr-p3rj-q5q6.json"