Vulnerability-Lookup

BREW-PNPM-CVE-2026-50021 (GHSA-Q6J5-FJX5-2MC3)

Vulnerability from osv_homebrew – Published: 2026-08-13 17:28 – Updated: 2026-09-16 10:03 – Source website

Summary

pnpm: Integrity Check Bypass via Missing Lockfile Integrity Field

Details

pnpm is a package manager. Prior to 10.34.0 and 11.4.0, pnpm's tarball extraction worker skips integrity verification when the integrity field is absent from the lockfile resolution. If an attacker can both modify pnpm-lock.yaml to remove the integrity: field and cause the referenced registry URL to serve altered package content, pnpm install --frozen-lockfile can install the altered package without an integrity error. npm's npm ci enforces integrity by default; pnpm's behavior of silently skipping verification is a pnpm-specific fail-open gap. This vulnerability is fixed in 10.34.0 and 11.4.0.

Severity

6.8 (Medium)


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

References

URL

Type

	https://github.com/CVEProject/cvelistV5/tree/main…	ADVISORY
	https://github.com/pnpm/pnpm/security/advisories/…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-50021	ADVISORY

JSON

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{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "upstream_fixed_in": "11.4.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "pnpm",
        "purl": "pkg:brew/pnpm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "11.21.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "git",
    "upstream_evidence": [
      {
        "ecosystem": "GIT",
        "key": "https://github.com/pnpm/pnpm",
        "name": "https://github.com/pnpm/pnpm",
        "strategy": "git",
        "subject_version": "v12.4.2"
      },
      {
        "ecosystem": "npm",
        "key": "pkg:npm/pnpm@12.4.2",
        "name": "pnpm",
        "strategy": "registry",
        "subject_version": "12.4.2"
      }
    ]
  },
  "details": "pnpm is a package manager. Prior to 10.34.0 and 11.4.0, pnpm\u0027s tarball extraction worker skips integrity verification when the integrity field is absent from the lockfile resolution. If an attacker can both modify pnpm-lock.yaml to remove the integrity: field and cause the referenced registry URL to serve altered package content, pnpm install --frozen-lockfile can install the altered package without an integrity error. npm\u0027s npm ci enforces integrity by default; pnpm\u0027s behavior of silently skipping verification is a pnpm-specific fail-open gap. This vulnerability is fixed in 10.34.0 and 11.4.0.",
  "id": "BREW-pnpm-CVE-2026-50021",
  "modified": "2026-09-16T10:03:26Z",
  "published": "2026-08-13T17:28:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50021.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/pnpm/pnpm/security/advisories/GHSA-q6j5-fjx5-2mc3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50021"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pnpm: Integrity Check Bypass via Missing Lockfile Integrity Field",
  "upstream": [
    "GHSA-q6j5-fjx5-2mc3",
    "CVE-2026-50021"
  ]
}

CVE-2026-50021 (GCVE-0-2026-50021)

Vulnerability from cvelistv5 – Published: 2026-06-25 16:48 – Updated: 2026-06-26 03:56

Title

pnpm: Integrity Check Bypass via Missing Lockfile Integrity Field

Summary

Severity

6.8 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-25 00:00 UTC

CWE

CWE-354 - Improper Validation of Integrity Check Value

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/pnpm/pnpm/security/advisories/…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
pnpm	pnpm	Affected: < 10.34.0 Affected: >= 11.0.0, < 11.4.0

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-50021",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-25T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-26T03:56:14.220Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/pnpm/pnpm/security/advisories/GHSA-q6j5-fjx5-2mc3"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "pnpm",
          "vendor": "pnpm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 10.34.0"
            },
            {
              "status": "affected",
              "version": "\u003e= 11.0.0, \u003c 11.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "pnpm is a package manager. Prior to 10.34.0 and 11.4.0, pnpm\u0027s tarball extraction worker skips integrity verification when the integrity field is absent from the lockfile resolution. If an attacker can both modify pnpm-lock.yaml to remove the integrity: field and cause the referenced registry URL to serve altered package content, pnpm install --frozen-lockfile can install the altered package without an integrity error. npm\u0027s npm ci enforces integrity by default; pnpm\u0027s behavior of silently skipping verification is a pnpm-specific fail-open gap. This vulnerability is fixed in 10.34.0 and 11.4.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-354",
              "description": "CWE-354: Improper Validation of Integrity Check Value",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-25T16:48:27.901Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pnpm/pnpm/security/advisories/GHSA-q6j5-fjx5-2mc3",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pnpm/pnpm/security/advisories/GHSA-q6j5-fjx5-2mc3"
        }
      ],
      "source": {
        "advisory": "GHSA-q6j5-fjx5-2mc3",
        "discovery": "UNKNOWN"
      },
      "title": "pnpm: Integrity Check Bypass via Missing Lockfile Integrity Field"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50021",
    "datePublished": "2026-06-25T16:48:27.901Z",
    "dateReserved": "2026-06-02T22:46:02.579Z",
    "dateUpdated": "2026-06-26T03:56:14.220Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-Q6J5-FJX5-2MC3

Vulnerability from github – Published: 2026-06-26 22:53 – Updated: 2026-06-26 22:53

Summary

pnpm Has an Integrity Check Bypass via Missing Lockfile Integrity Field

Details

Summary

pnpm's tarball extraction worker skips integrity verification when the integrity field is absent from the lockfile resolution. If an attacker can both modify pnpm-lock.yaml to remove the integrity: field and cause the referenced registry URL to serve altered package content, pnpm install --frozen-lockfile can install the altered package without an integrity error. npm's npm ci enforces integrity by default; pnpm's behavior of silently skipping verification is a pnpm-specific fail-open gap.

Vulnerability Details

The addTarballToStore function in worker/src/start.ts (lines 189-204) checks if (integrity) before verifying the tarball hash. The TarballResolution type declares integrity as optional (integrity?: string). When the lockfile omits the integrity field, the guard evaluates to false, skipping hash verification entirely. The worker then computes a new hash from the unverified content and stores it as legitimate.

// worker/src/start.ts:189-204
function addTarballToStore ({ buffer, storeDir, integrity, ... }: TarballExtractMessage) {
  if (integrity) {           // false when integrity is undefined
    const { algorithm, hexDigest } = parseIntegrity(integrity)
    const calculatedHash = crypto.hash(algorithm, buffer, 'hex')
    if (calculatedHash !== hexDigest) {
      return { status: 'error', error: { type: 'integrity_validation_failed', ... } }
    }
  }
  return {
    status: 'success',
    value: { integrity: integrity ?? calcIntegrity(buffer) },
  }
}

Proof of Concept

bash autofyn_audit/exploits/vuln1_integrity_bypass/exploit.sh
# Publishes a package, generates lockfile, republishes tampered version,
# strips integrity field, re-runs install --frozen-lockfile.
# Result: PASS -- tampered package installed without integrity error.

Impact

Supply chain compromise in environments where an attacker can both alter the lockfile and cause the referenced registry URL to serve altered package content. The --frozen-lockfile flag does not fail closed when the integrity field is missing.

Suggested Remediation

Require an integrity field for remote tarball resolutions. Change the if (integrity) guard to fail when integrity is absent for non-local packages. When --frozen-lockfile is active, reject lockfile entries that lack integrity for remote packages.

Discovered by AutoFyn Full audit report: audit_report.md Exploit script: exploit.sh

Severity

6.8 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "pnpm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.0.0"
            },
            {
              "fixed": "11.4.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "pnpm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "10.34.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50021"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-354"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-26T22:53:01Z",
    "nvd_published_at": "2026-06-25T18:16:39Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\npnpm\u0027s tarball extraction worker skips integrity verification when the `integrity` field is absent from the lockfile resolution. If an attacker can both modify `pnpm-lock.yaml` to remove the `integrity:` field and cause the referenced registry URL to serve altered package content, `pnpm install --frozen-lockfile` can install the altered package without an integrity error. npm\u0027s `npm ci` enforces integrity by default; pnpm\u0027s behavior of silently skipping verification is a pnpm-specific fail-open gap.\n\n## Vulnerability Details\n\nThe `addTarballToStore` function in `worker/src/start.ts` (lines 189-204) checks `if (integrity)` before verifying the tarball hash. The `TarballResolution` type declares `integrity` as optional (`integrity?: string`). When the lockfile omits the `integrity` field, the guard evaluates to `false`, skipping hash verification entirely. The worker then computes a new hash from the unverified content and stores it as legitimate.\n\n```typescript\n// worker/src/start.ts:189-204\nfunction addTarballToStore ({ buffer, storeDir, integrity, ... }: TarballExtractMessage) {\n  if (integrity) {           // false when integrity is undefined\n    const { algorithm, hexDigest } = parseIntegrity(integrity)\n    const calculatedHash = crypto.hash(algorithm, buffer, \u0027hex\u0027)\n    if (calculatedHash !== hexDigest) {\n      return { status: \u0027error\u0027, error: { type: \u0027integrity_validation_failed\u0027, ... } }\n    }\n  }\n  return {\n    status: \u0027success\u0027,\n    value: { integrity: integrity ?? calcIntegrity(buffer) },\n  }\n}\n```\n\n## Proof of Concept\n\n```bash\nbash autofyn_audit/exploits/vuln1_integrity_bypass/exploit.sh\n# Publishes a package, generates lockfile, republishes tampered version,\n# strips integrity field, re-runs install --frozen-lockfile.\n# Result: PASS -- tampered package installed without integrity error.\n```\n\n## Impact\n\nSupply chain compromise in environments where an attacker can both alter the lockfile and cause the referenced registry URL to serve altered package content. The `--frozen-lockfile` flag does not fail closed when the integrity field is missing.\n\n## Suggested Remediation\n\nRequire an `integrity` field for remote tarball resolutions. Change the `if (integrity)` guard to fail when integrity is absent for non-local packages. When `--frozen-lockfile` is active, reject lockfile entries that lack integrity for remote packages.\n\n---\n\n\u003e Discovered by [AutoFyn](https://github.com/SignalPilot-Labs/AutoFyn)\n\u003e Full audit report: [audit_report.md](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/audit_report.md)\n\u003e Exploit script: [exploit.sh](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/exploits/vuln1_integrity_bypass/exploit.sh)",
  "id": "GHSA-q6j5-fjx5-2mc3",
  "modified": "2026-06-26T22:53:01Z",
  "published": "2026-06-26T22:53:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pnpm/pnpm/security/advisories/GHSA-q6j5-fjx5-2mc3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50021"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pnpm/pnpm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pnpm Has an Integrity Check Bypass via Missing Lockfile Integrity Field"
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

BREW-PNPM-CVE-2026-50021 (GHSA-Q6J5-FJX5-2MC3)

CVE-2026-50021 (GCVE-0-2026-50021)

GHSA-Q6J5-FJX5-2MC3

Summary

Vulnerability Details

Proof of Concept

Impact

Suggested Remediation

Tags

Sightings

Nomenclature

Related by attack behaviour