FKIE_CVE-2026-39395

Vulnerability from fkie_nvd - Published: 2026-04-07 20:16 - Updated: 2026-04-15 15:57
Severity ?
4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Summary
Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.
References
security-advisories@github.comhttps://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6Mitigation, Vendor Advisory
Impacted products
Vendor Product Version
sigstore cosign *
sigstore cosign *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:sigstore:cosign:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E1C20B41-D20F-4FC4-AFD6-00C45B60CC58",
              "versionEndExcluding": "2.6.3",
              "vulnerable": true
            },
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          "negate": false,
          "operator": "OR"
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a \"Verified OK\" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3."
    }
  ],
  "id": "CVE-2026-39395",
  "lastModified": "2026-04-15T15:57:49.283",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
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        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
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        "impactScore": 1.4,
        "source": "nvd@nist.gov",
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  "published": "2026-04-07T20:16:33.140",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
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      "url": "https://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6"
    }
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  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
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          "value": "CWE-754"
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      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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