GHSA-9VCR-P3RJ-Q5Q6
Vulnerability from github – Published: 2026-07-09 23:20 – Updated: 2026-07-09 23:20Impact
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.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.1.4"
},
"package": {
"ecosystem": "Go",
"name": "github.com/sigstore/sigstore-go"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-49834"
],
"database_specific": {
"cwe_ids": [
"CWE-345"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-09T23:20:30Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nA verifier configured with WithTransparencyLog(N\u003e1) or WithSignedCertificateTimestamps(N\u003e1) 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.\n\nAs 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.\n\nNote that this does not affect Cosign, as Cosign sets a threshold of 1.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\nUpgrade to v1.1.5.\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nThere is no workaround, beyond relying on trusted logs.",
"id": "GHSA-9vcr-p3rj-q5q6",
"modified": "2026-07-09T23:20:30Z",
"published": "2026-07-09T23:20:30Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/sigstore/sigstore-go/security/advisories/GHSA-9vcr-p3rj-q5q6"
},
{
"type": "PACKAGE",
"url": "https://github.com/sigstore/sigstore-go"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "sigstore-go has a multi-log threshold bypass via single compromised log"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.