Vulnerability library
Security checkOctober 20, 2026

ApostropheCMS: Unauthenticated unbounded multipart upload → disk-exhaustion DoS

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Medium severitynpm@apostrophecms/form

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Description

Summary The form submission endpoint runs multer({ dest: os.tmpdir() }).any() before authentication, API-key, CSRF-equivalent, or form-existence logic, with no size/count/rate limits. Unauthenticated users can stream unbounded bodies to disk per request; cleanup occurs only after the full body is received.

Details packages/form/index.js apiRoutes.post.submit (L274–296): [ multer({ dest: os.tmpdir() }).any(), self.normalizeFiles, async function (req) { try { submitForm } finally { unlink files } } ]. No limits, no rate limiting, no pre-validation. “CSRF” is a fixed-value double-submit cookie (vulnlab.csrf=csrf, set on any GET, express/index.

Recommendation

Update the @apostrophecms/form package to the latest compatible version. Followings are version details:

  • Affected version(s): < 1.5.5
  • Patched version(s): 1.5.5

References

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Related Issues

See something that needs correcting? Let us knowUpdated October 20, 2026