{
  "schema_version": "1.4.0",
  "id": "GHSA-xgjw-pm74-86q4",
  "modified": "2026-07-01T19:57:45Z",
  "published": "2026-07-01T19:57:45Z",
  "aliases": [
    "CVE-2026-48816"
  ],
  "summary": "sigstore-js has Insufficient Verification of Data Authenticity",
  "details": "sigstore-js derives a transparency-log timestamp from `tlogEntries[].integratedTime` and uses it to validate certificate validity windows and satisfy `timestampThreshold`. For bundle v0.2, a tlog entry can be inclusionProof-only (no signed inclusionPromise/set), and the inclusion proof path does not cryptographically bind `integratedTime`. As a result, an attacker who can supply an untrusted bundle can influence time-based verification decisions by choosing `integratedTime`.\n\n## impact\nIf a consumer accepts attacker-provided bundle v0.2 inputs and relies on tlog-derived timestamps for certificate validity checks, verification can be influenced by an unauthenticated timestamp value. This is a trust gap: `integratedTime` is treated as a trusted observer timestamp under inclusionProof-only mode even though only the signed inclusionPromise/set path binds it.\n\n## affected code\n- `packages/verify/src/bundle/index.ts` (adds a transparency-log timestamp whenever `integratedTime != 0`)\n- `packages/verify/src/timestamp/index.ts` (converts `integratedTime` to a `Date`)\n- `packages/verify/src/verifier.ts` (verifies timestamps before verifying tlog inclusion)\n- `packages/verify/src/tlog/index.ts` + `packages/verify/src/tlog/set.ts` (only the inclusionPromise/set path binds `integratedTime`)\n\n## proof of concept\nThe attached `poc.zip` contains a self-contained harness that reproduces the behavior on the pinned commit and includes both a canonical test and a negative control.\n\nrepro:\n1) extract `poc.zip` into a fresh directory and run the make targets:\n\n```bash\nunzip poc.zip -d poc\ncd poc/poc-F-SIG-JS-TLOGTIME-001\nmake canonical\nmake control\n```\n\n2) confirm `canonical.log` includes:\n\n```\n[CALLSITE_HIT]:\n[PROOF_MARKER]:\n```\n\n3) confirm `control.log` includes:\n\n```\n[NC_MARKER]:\n```\n\n## suggested fix\nOnly treat `integratedTime` as a trusted timestamp when it is cryptographically bound (for example, via a verified signed inclusionPromise/set). For inclusionProof-only entries, do not count `integratedTime` toward `timestampThreshold`, and do not use it for certificate validity decisions unless there is another signed time source (for example, an rfc3161 timestamp).\n\n[poc.zip](https://github.com/user-attachments/files/25643656/poc.zip)\n[PR_DESCRIPTION.md](https://github.com/user-attachments/files/25643660/PR_DESCRIPTION.md)\n[SUBMISSION.md](https://github.com/user-attachments/files/25643662/SUBMISSION.md)",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@sigstore/verify"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "3.1.0"
            },
            {
              "fixed": "3.1.1"
            }
          ]
        }
      ],
      "versions": [
        "3.1.0"
      ]
    }
  ],
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sigstore/sigstore-js/security/advisories/GHSA-xgjw-pm74-86q4"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sigstore/sigstore-js"
    }
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-345"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-01T19:57:45Z",
    "nvd_published_at": null
  }
}