{"id":"CVE-2026-14257","revision":null,"records":[{"revision":"8498532188be42f0a23e426c7bace4c2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-14257","aliases":[],"title":"brace-expansion DoS via unbounded expansion length causing an out-of-memory process crash","description":"brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining multiple brace groups, an attacker keeps the result count under the limit while making each result progressively longer, so total memory scales with both count and string length until the process hits a fatal, uncatchable out-of-memory error. About 7.5 KB of input ('{a,b}'.repeat(1500)) crashes a default Node.js process. Any application that passes attacker-influenced strings to brace-expansion.expand() - directly or transitively via minimatch / glob brace patterns - can be crashed by a small request. Fixed in 5.0.8 by adding a maxLength option (default 4,000,000) that bounds accumulated output and intermediate arrays.","state":0,"publishedAt":"2026-07-23T12:54:23.124+00:00","modifiedAt":"2026-07-23T14:44:41.856+00:00","affected":[{"ecosystem":"https://www.npmjs.com/package/brace-expansion","name":"brace-expansion","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"juliangruber\",\n                    \"product\": \"brace-expansion\",\n                    \"platforms\": [\n                        \"Linux\",\n                        \"macOS\",\n                        \"Windows\"\n                    ],\n                    \"collectionURL\": \"https://www.npmjs.com/package/brace-expansion\",\n                    \"packageName\": \"brace-expansion\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThanOrEqual\": \"5.0.7\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://www.npmjs.com/package/brace-expansion","https://github.com/juliangruber/brace-expansion","https://github.com/juliangruber/brace-expansion/commit/a1bd33999ea75262c4749fff3bbb0d1372bd07b5"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-14257","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-14257","identifiers":["CVE-2026-14257"]},"retained":false,"historicalAffected":[]},{"revision":"ed4bf1b552374aa184e3b00db8eefec1","observedAt":"2026-10-25T05:17:25.909+00:00","statement":{"source":"nvd","id":"CVE-2026-14257","aliases":[],"title":"brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining …","description":"brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining multiple brace groups, an attacker keeps the result count under the limit while making each result progressively longer, so total memory scales with both count and string length until the process hits a fatal, uncatchable out-of-memory error. About 7.5 KB of input ('{a,b}'.repeat(1500)) crashes a default Node.js process. Any application that passes attacker-influenced strings to brace-expansion.expand() - directly or transitively via minimatch / glob brace patterns - can be crashed by a small request. Fixed in 5.0.8 by adding a maxLength option (default 4,000,000) that bounds accumulated output and intermediate arrays.","state":0,"publishedAt":"2026-07-23T14:17:00.25+00:00","modifiedAt":"2026-10-24T13:10:00.147+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · 22e2d327-25fe-45d7-9f0c-dcd23b7108df · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://github.com/juliangruber/brace-expansion","https://github.com/juliangruber/brace-expansion/commit/a1bd33999ea75262c4749fff3bbb0d1372bd07b5","https://www.npmjs.com/package/brace-expansion"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-14257","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-400","CWE-770"],"productCriteria":["cpe:2.3:a:juliangruber:brace-expansion:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-07-23T14:17:00.250","lastModified":"2026-10-24T13:10:00.147"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-14257","identifiers":["CVE-2026-14257"]},"retained":false,"historicalAffected":[]},{"revision":"5f708d0f9b844e3c8df52978b85095e1","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-mh99-v99m-4gvg","aliases":["CVE-2026-14257"],"title":"brace-expansion: DoS via unbounded expansion length causing an out-of-memory process crash","description":"### Summary\n\n`expand()` bounds the *number* of results it produces (the `max` option,\n`100_000` by default) but not their *length*. By chaining many brace groups,\nan attacker keeps the result count under `max` while making every result grow\nwith the number of groups. Building `max` long results — plus the intermediate\narrays combined at each brace group — exhausts memory and crashes the Node\nprocess with an **uncatchable** out-of-memory error. `try/catch` around\n`expand()` does not help: the fatal error terminates the process.\n\nA ~7.5 KB input (`'{a,b}'.repeat(1500)`) is enough to crash a default Node\nprocess.\n\n### Details\n\nFor `N` chained brace groups such as `'{a,b}'.repeat(N)`:\n\n- the result count is `2^N`, immediately capped at `max` (`100_000`), so the\n  `max` protection appears to hold, but\n- each result is `N` characters long, so the total output size is\n  `max × N` characters, which grows without bound in `N`.\n\n`expand_` combines each brace set with the fully-expanded tail:\n\n```js\nconst post = m.post.length ? expand_(m.post, max, false) : ['']\n...\nfor (let j = 0; j < N.length; j++) {\n  for (let k = 0; k < post.length && expansions.length < max; k++) {\n    const expansion = pre + N[j] + post[k]   // grows one group longer per level\n    ...\n    expansions.push(expansion)\n  }\n}\n```\n\nThe loop guard `expansions.length < max` limits how many strings are built, but\nnothing limits how long they get. Each recursion level materializes another\narray of up to `max` strings, one character longer than the level below, and —\nbecause V8 represents `pre + N[j] + post[k]` as a cons-string (rope) that\nreferences `post[k]` — those intermediate strings stay reachable through the\nwhole chain. Memory therefore scales with `max × N`.\n\nMeasured on `5.0.7` (`'{a,b}'.repeat(N)`, default `max`):\n\n| groups (N) | input bytes | result count | peak RSS |\n|---|---|---|---|\n| 20 | 100 | 100,000 | ~80 MB |\n| 50 | 250 | 100,000 | ~214 MB |\n| 100 | 500 | 100,000 | ~409 MB |\n| 300 | 1,500 | 100,000 | ~1,148 MB |\n| 1500 | 7,500 | — | **OOM crash** |\n\n### Proof of concept\n\n```js\nconst { expand } = require('brace-expansion')\n\n// ~7.5 KB input — crashes the process with a fatal, uncatchable OOM:\n//   FATAL ERROR: ... JavaScript heap out of memory\ntry {\n  expand('{a,b}'.repeat(1500))\n} catch (e) {\n  // never reached — the process is already dead\n}\n```\n\n### Impact\n\nAny application that passes attacker-influenced strings to\n`brace-expansion.expand()` — directly, or transitively via `minimatch` / `glob`\nbrace patterns — can be crashed by a small request. Because the failure is a\nfatal V8 out-of-memory error rather than a thrown exception, it cannot be caught\nand it takes down the whole worker/process, denying service.\n\n### Remediation\n\nUpgrade to a patched release. The fix bounds the total number of characters a\nsingle `expand()` call may accumulate (`EXPANSION_MAX_LENGTH`, default\n`4_000_000`, configurable via a new `maxLength` option), applied inside the\noutput-building loops so intermediate arrays are bounded too. Once the limit is\nreached, output is truncated — consistent with how `max` already truncates —\ninstead of growing without bound. The limit sits well above any realistic\nexpansion (100,000 results hitting `max` measure ~1M characters), so legitimate\ninput is unaffected.\n\nAfter the fix, `'{a,b}'.repeat(1500)` returns a bounded, truncated result in\n~0.7 s using ~340 MB and never crashes, including under a constrained 512 MB\nheap.\n\nThe fix bounds memory but the algorithm still rebuilds intermediate arrays at\neach level (roughly `O(N × maxLength)` work on this input class). A streaming\nrewrite that produces output in `O(total output size)` can be a non-urgent\nfollow-up.\n\nIf immediate upgrade isn't possible, avoid passing untrusted input to\n`expand()` / glob brace patterns, or pass a small explicit `max` **and**\n`maxLength`.","state":0,"publishedAt":"2026-07-24T21:53:14+00:00","modifiedAt":"2026-09-10T03:50:12.2828493+00:00","affected":[{"ecosystem":"npm","name":"brace-expansion","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"4.0.0"},{"kind":"fixed","version":"5.0.8"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"brace-expansion","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"3.0.0"},{"kind":"fixed","version":"3.0.3"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"brace-expansion","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"2.0.0"},{"kind":"fixed","version":"2.1.3"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"brace-expansion","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"1.1.17"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/juliangruber/brace-expansion/security/advisories/GHSA-mh99-v99m-4gvg","https://nvd.nist.gov/vuln/detail/CVE-2026-14257","https://github.com/juliangruber/brace-expansion/pull/129","https://github.com/juliangruber/brace-expansion/pull/130","https://github.com/juliangruber/brace-expansion/pull/136","https://github.com/juliangruber/brace-expansion/commit/139d015104e71433ad52a41d19467c48ecbb2c7d","https://github.com/juliangruber/brace-expansion/commit/a1bd33999ea75262c4749fff3bbb0d1372bd07b5","https://github.com/juliangruber/brace-expansion/commit/cb4b9e47cc2ec777c14b2b4492fb431a56f6a031","https://github.com/juliangruber/brace-expansion/commit/d13ff455a58b0d56704f0111e3c2a0b16ceb06eb","https://github.com/juliangruber/brace-expansion","https://www.npmjs.com/package/brace-expansion"],"sourceUrl":"https://github.com/advisories/GHSA-mh99-v99m-4gvg","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-mh99-v99m-4gvg","identifiers":["GHSA-mh99-v99m-4gvg","CVE-2026-14257"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-10-26T05:26:56.6538334+00:00","complete":true,"records":1756,"lastAttemptAt":"2026-10-26T05:26:56.6538334+00:00","lastSuccessAt":"2026-10-26T05:26:56.7986454+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:26:56.7986482+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-5ba1945314e042c2ced14b33f3680fa71692812d925544312b218f5eb8a26e71-bc703d32c448acb7291b43dd467a47b987ad86f105a430a0e30b03cf6e038792","complete":true,"records":414069,"lastAttemptAt":"2026-10-26T05:25:21.6088408+00:00","lastSuccessAt":"2026-10-26T05:25:21.5943862+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:25:21.6088408+00:00","snapshotPublishedAt":"2026-10-26T04:31:21+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-43321610382942b8ad8c85917eab1546","complete":false,"records":4735,"lastAttemptAt":"2026-10-26T05:26:59.285199+00:00","lastSuccessAt":"2026-10-24T23:18:49.862+00:00","error":"InvalidDataException","lastVerifiedAt":"2026-10-24T23:18:49.862+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":4764,"expectedIdentifiers":13474},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-10-26T05:26:56.6538334+00:00","complete":true,"records":1093,"lastAttemptAt":"2026-10-26T05:26:56.6538334+00:00","lastSuccessAt":"2026-10-26T05:26:56.7998442+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:26:56.799845+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-204a3fb93a00487e8f7f36db01dc851d","complete":true,"records":13413,"lastAttemptAt":"2026-10-26T05:26:57.2787164+00:00","lastSuccessAt":"2026-10-25T16:19:28.681+00:00","error":null,"lastVerifiedAt":"2026-10-25T16:19:28.681+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13474,"expectedIdentifiers":13474},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-2375a4e597279abf92e8747e140fe8da9d421877cd49cae3ac69a2cb78469b2c","complete":true,"records":9779,"lastAttemptAt":"2026-10-26T05:26:56.2433127+00:00","lastSuccessAt":"2026-10-24T13:19:53.1346702+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:26:56.2433127+00:00","snapshotPublishedAt":"2026-10-24T03:03:12+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-16ad89dfea13ab9e9b0108e63a759d63bd4559cc68b58491107d62ee35bbbaf2","complete":true,"records":1965,"lastAttemptAt":"2026-10-26T05:25:21.7989429+00:00","lastSuccessAt":"2026-10-23T16:01:26.4487605+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:25:21.7989429+00:00","snapshotPublishedAt":"2026-10-21T12:18:07+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-7da67a15aa6e56a0e3081a7646dc74d537e6ef974afc593c2b1794ed01970648","complete":true,"records":2969,"lastAttemptAt":"2026-10-26T05:26:56.6198554+00:00","lastSuccessAt":"2026-10-24T13:19:59.1145547+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:26:56.6198554+00:00","snapshotPublishedAt":"2026-10-24T08:47:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f936be991545888acd70d1c7b6fcb3da4be35405bbec4bff46b924c2832f41b1","complete":true,"records":230802,"lastAttemptAt":"2026-10-26T05:26:56.1119243+00:00","lastSuccessAt":"2026-10-26T05:26:54.9585845+00:00","error":null,"lastVerifiedAt":"2026-10-26T05:26:56.1119243+00:00","snapshotPublishedAt":"2026-10-26T04:48:14+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null}]}