{"schema":"threatline.record/2","record":{"id":"CVE-2026-113656","aliases":["GHSA-89mh-mm8c-mv7f"],"summary":"ApostropheCMS: Unauthenticated unbounded multipart upload → disk-exhaustion DoS","details":"**Summary**\nThe 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.\n\n**Details**\n`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.js L694–703) — trivially obtainable anonymously.\n\n**PoC**\n```\n$ curl -s -c csrfjar.cookies http://localhost:3100/        # get vulnlab.csrf=csrf (any GET)\n$ df -P /tmp                                                # before: used=1105212\n$ curl -b csrfjar.cookies -X POST http://localhost:3100/api/v1/@apostrophecms/form/submit \\\n      -F \"file=@/tmp/opencode/big.bin;type=application/octet-stream\" &\n   DURING transfer:    used=1148668\n   still transferring: used=1226936        # +121MB mid-transfer on disk\n   http=500 time=1.78s sent=209715411B     # generic error AFTER full staging\n# Anonymous, zero credentials. 200MB written to /tmp pre-validation.\n```\n\n**Impact**\nAny unauthenticated client can force the server to persist entire request bodies to the temp filesystem and CPU-decode them; parallel requests exhaust disk `/tmp` (process/host crash) and saturate the event loop — a trivial remote DoS. Aborted transfers risk orphaning staged files (no `req.aborted` cleanup).\n\n\n**Remediation** — Set multer `limits` (fileSize, fields, parts, fieldSize); perform auth/role/existence checks before the multer mount or inside the checked handler; unlink staged files on first read and on `req.aborted`/error; add per-IP rate limiting.","categories":["Libraries & packages"],"product":"@apostrophecms/form","vendor":"apostrophecms","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-89mh-mm8c-mv7f","source_modified_at":"2026-10-20T18:08:32Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@apostrophecms/form"},"range":"< 1.5.5"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-113656","source_modified_at":"2026-10-21T15:53:31.741Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"apostrophe","vendor":"apostrophecms","versions":[{"status":"affected","version":"< 4.33.0"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-113656","source_modified_at":"2026-10-21T15:53:31.741Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"form","vendor":"@apostrophecms","versions":[{"status":"affected","version":"< 1.5.5"}],"defaultStatus":null},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-89mh-mm8c-mv7f","source_modified_at":"2026-10-20T18:15:04.526192205Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"@apostrophecms/form","ecosystem":"npm","purl":"pkg:npm/%40apostrophecms/form"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.5.5"}]}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-89mh-mm8c-mv7f","source_modified_at":"2026-10-20T18:08:32Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@apostrophecms/form"},"version":"1.5.5"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-89mh-mm8c-mv7f","source_modified_at":"2026-10-20T18:15:04.526192205Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"@apostrophecms/form","ecosystem":"npm","purl":"pkg:npm/%40apostrophecms/form"},"version":"1.5.5"}],"cvss":5.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00437,"percentile":0.36965,"score_date":"2026-10-23"},"published_at":"2026-10-20T16:49:36.239Z","modified_at":"2026-10-21T15:53:31.741Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-89mh-mm8c-mv7f","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-20T18:08:32Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-113656","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T15:53:31.741Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-89mh-mm8c-mv7f","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-10-20T18:15:04.526192205Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-113656","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["GitHub Advisory Database","CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-89mh-mm8c-mv7f","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/form@1.5.5","tags":["x_refsource_MISC"]},{"url":"https://github.com/advisories/GHSA-89mh-mm8c-mv7f","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-10-21T14:40:27.714281Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T15:53:31.741Z","content_hash":"5190be5f5e169a0c812f08c741917b19ca5e02eb414f56de63df3c20e7e35354"}}