brace-expansion: DoS via uncontrolled recursion in parseCommaParts causing stack exhaustion

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to 1.1.19, 2.1.5, 3.0.7, and 5.0.10, crafted brace patterns can exhaust the native stack in parseCommaParts because parseCommaParts recursively processes the remainder once per brace group and uses push.apply to pass every element of a very large comma-part array as a function argument. Patterns containing many comma-separated brace groups trigger the recursive path, while the large array triggers the argument-array path without deep recursion. These paths cause recursive and argument-array native stack exhaustion before max or maxLength can limit output, potentially terminating the Node.js process in a process-terminating denial of service. This issue is fixed in versions 1.1.19, 2.1.5, 3.0.7, and 5.0.10.

Source published

28 Sep 2026 20:50:59 UTC

Source modified

29 Sep 2026 13:38:29 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to 1.1.19, 2.1.5, 3.0.7, and 5.0.10, crafted brace patterns can exhaust the native stack in parseCommaParts because parseCommaParts recursively processes the remainder once per brace group and uses push.apply to pass every element of a very large comma-part array as a function argument. Patterns containing many comma-separated brace groups trigger the recursive path, while the large array triggers the argument-array path without deep recursion. These paths cause recursive and argument-array native stack exhaustion before max or maxLength can limit output, potentially terminating the Node.js process in a process-terminating denial of service. This issue is fixed in versions 1.1.19, 2.1.5, 3.0.7, and 5.0.10.

Source published

Sep 28, 2026, 8:50:59 PM (timezone not stated)

Source modified

Sep 29, 2026, 1:38:29 PM (timezone not stated)

Observed here

11 Nov 2026 05:28:45 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to 1.1.19, 2.1.5, 3.0.7, and 5.0.10, crafted brace patterns can exhaust the native stack in parseCommaParts because parseCommaParts recursively processes the remainder once per brace group and uses push.apply to pass every element of a very large comma-part array as a function argument. Patterns containing many comma-separated brace groups trigger the recursive path, while the large array triggers the argument-array path without deep recursion. These paths cause recursive and argument-array native stack exhaustion before max or maxLength can limit output, potentially terminating the Node.js process in a process-terminating denial of service. This issue is fixed in versions 1.1.19, 2.1.5, 3.0.7, and 5.0.10.

Source published

28 Sep 2026 21:17:16 UTC

Source modified

30 Sep 2026 19:57:08 UTC

Observed here

25 Oct 2026 04:17:26 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

### Summary `parseCommaParts()` can exhaust the native stack and crash the process. There are two distinct ways to trigger it, both reachable from a single untrusted pattern string. This is the parsing-side counterpart to CVE-2026-14257 / GHSA-mh99-v99m-4gvg. That fix made `expand_()` iterative and documented a constant-stack-depth guarantee, but `parseCommaParts()` was left recursive, so the guarantee only held for one of the two parsing paths. ### Vector 1 - unbounded recursion on `post` `parseCommaParts()` recursed on the remainder of the string once per brace group: ```js const postParts = parseCommaParts(post) // unbounded ``` A brace group containing many comma-separated groups drives one recursion level per group: ```js expand('{' + '{a},'.repeat(7000) + 'b}') // RangeError: Maximum call stack size exceeded ``` About 7,300 repetitions - roughly 29 KB of input - is enough on Node 24; roughly 6,300 (25 KB) on Node 18. The threshold is identical on every affected release line. ### Vector 2 - `push.apply` with an unbounded array Even with the recursion removed, `parseCommaParts()` spread whole arrays into an argument list: ```js p.push.apply(p, postParts) parts.push.apply(parts, p) ``` `Function.prototype.apply` places one argument per element on the stack, so a single large array overflows it. This needs **no recursion depth at all** - the following reaches a recursion depth of exactly 1: ```js expand('{{x},' + 'a,'.repeat(125000) + 'b}') // RangeError: Maximum call stack size exceeded ``` Threshold is about 124,300 repetitions (~249 KB). This vector was not part of the original report; it was found while verifying the fix. A patch that only de-recurses but keeps `push.apply` leaves a working denial of service behind. ### Why `max` and `maxLength` do not help Both crashes happen during **parsing**, before any expansion. The payloads produce one result per group, so output size grows linearly with input and is never the limiter. `expand(payload, { max: 1, maxLength: 1 })` still overflows. ### Impact Any application that passes an untrusted string to `expand()` - directly, or through `minimatch` / `glob` where it is a user-supplied glob pattern - can be crashed. In Node, a `RangeError` that the application does not catch terminates the process, so a server that globs user input is exposed to remote unauthenticated denial of service. `minimatch`'s own `MAX_PATTERN_LENGTH` cap (65,536) does not help against vector 1: the overflow threshold sits well below it. Confirmed on minimatch 10.2.6 - a 64,003-byte pattern passes the length check and overflows both `minimatch.braceExpand()` and `new minimatch.Minimatch()`. This is an availability-only issue. No code execution and no data exposure. ### Not a regression 5.0.8 and 5.0.9 overflow at the same repetition count, so the gap predates the recent advisories; those fixes simply did not reach it. Verified affected on 1.1.18, 2.1.4, 3.0.6, 5.0.8 and 5.0.9, all at an identical threshold. ### Patch `parseCommaParts()` is rewritten as a loop that carries the partial part across chunks, and every array append uses an element-by-element loop rather than `push.apply`. The redundant `if (!str) return ['']` guard is dropped - the loop returns `['']` for the empty string on its own. Equivalence of the old and new implementations was checked by differential testing: exhaustive over every string of `{`, `}`, `,`, `a` up to length 7 plus 300,000 random inputs - 322,000 cases, zero mismatches. ### Severity note Scored 7.5 High under CVSS 3.1 for consistency with the other availability advisories on this package (GHSA-mh99-v99m-4gvg, GHSA-rgw5-rvv9-x895), which use the same vector. The reporter self-assessed 6.9 Medium under CVSS 4.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`). ### Credit Reported by baeseungwon1010, with a working proof of concept and a proposed patch. Vector 2 was identified during maintainer verification.

Source published

29 Sep 2026 23:44:58 UTC

Source modified

30 Sep 2026 00:00:03 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH