chore(deps): update dependency brace-expansion@<1.1.13 to v5 [security] by renovate[bot] · Pull Request #267 · cyberuni/path-equal

renovate · 2026-10-04T23:42:22Z

This PR contains the following updates:

Package	Change	Age	Confidence
brace-expansion@<1.1.13	`^1.1.18` → `^5.0.12`

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

CVE-2026-102276 / GHSA-6j4f-fj2g-mc7p

More information

Details

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:

const postParts = parseCommaParts(post)   // unbounded

A brace group containing many comma-separated groups drives one recursion level per group:

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:

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:

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.

Severity

CVSS Score: 7.5 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

brace-expansion: DoS via uncontrolled recursion on nested brace groups causing stack exhaustion

CVE-2026-102278 / GHSA-qhr7-859c-m2p7

More information

Details

Summary

expand_() recurses once per level of brace nesting. Deeply nested input exhausts the native stack and crashes the process.

This is distinct from CVE-2026-14257 / GHSA-mh99-v99m-4gvg, which made the tail iterative (recursion on m.post, driven by how many groups are chained). Nesting depth drives a different recursion that the tail fix never touched, so the documented constant-stack-depth guarantee only ever covered chained input, not nested input.

It is also distinct from GHSA-6j4f-fj2g-mc7p, which fixed recursion in parseCommaParts(). Both payloads below still crash with that fix applied.

Two recursion sites

Comma members. Each alternative of a brace set is expanded by a recursive call, so nesting a set inside every alternative recurses once per level:

expand('{a,'.repeat(4000) + 'z' + '}'.repeat(4000))
// RangeError: Maximum call stack size exceeded

Crashes at depth 3,907 - about 15.6 KB of input.

Single set. A brace set whose body parses to a single part is expanded by a recursive call before being re-wrapped (x{{a,b}}y -> x{a}y x{b}y), which recurses once per nesting level:

expand('{'.repeat(3200) + 'a,b' + '}'.repeat(3200))
// RangeError: Maximum call stack size exceeded

Crashes at depth 3,125 - about 6.25 KB of input. This is the cheapest stack-exhaustion payload known against this package: roughly a quarter the input of GHSA-6j4f-fj2g-mc7p (29 KB), and about a tenth of minimatch's MAX_PATTERN_LENGTH (65,536).

Why `max` and `maxLength` do not help

Both crashes happen while recursing into sub-expansions, before the result set grows. The payloads produce almost no output - the single-set case yields 2 results - so neither bound is ever the limiter. expand(payload, { max: 1, maxLength: 1 }) still overflows.

Impact

Any application passing an untrusted string to expand(), directly or through minimatch / glob as a user-supplied glob pattern, can be crashed. In Node a RangeError the application does not catch terminates the process, so a server globbing user input is exposed to remote unauthenticated denial of service.

Availability only. No code execution, no data exposure.

Affected versions

Verified affected on 1.1.18, 2.1.4, 3.0.6 and 5.0.9, at near-identical depths on every line (single set: 3,125 on all four; comma members: 3,907-4,102). Not a regression from any recent fix - the gap predates them.

Patch

A maxDepth bound (default EXPANSION_MAX_DEPTH) is threaded through expand_(). Past the cap a group is treated as non-expanding and returned literally, which is how the parser already handles a group that cannot expand. This matches the existing max / maxLength caps, which truncate rather than throw, so expand() continues never to throw on any input.

The default sits far above any realistic nesting depth and well below the crash threshold.

Severity

CVSS Score: 7.5 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service

CVE-2026-102277 / GHSA-q2hr-2g5m-vwhr

More information

Details

Summary

Expanding {a},b}-shaped input takes time quadratic in the number of literal } characters, blocking the event loop.

Bash preserves a quirk where a brace group followed by a comma set still expands ({a},b}). The parser implements this by rewriting the string and restarting the scan. Each pass absorbs exactly one } and re-scans from the beginning, so n trailing braces cost n full passes.

Reproduction

const build = n => '{a}' + '}'.repeat(n) + ',z}'

for (const n of [8000, 16000, 32000, 64000, 128000]) {
  const t = Date.now()
  expand(build(n))
  console.log(n, Date.now() - t + 'ms')
}

n	input	time	results
8,000	8 KB	110 ms	2
16,000	16 KB	446 ms	2
32,000	32 KB	1.7 s	2
64,000	64 KB	6.9 s	2
128,000	128 KB	27.7 s	2

ms/n^2 is flat at ~1.7 and each doubling of n costs exactly 4.0x - quadratic. 128 KB of input blocks the event loop for nearly half a minute to produce two results.

Mechanism

Instrumenting the rewrite branch confirms it runs exactly n + 1 times, once per literal }, each re-scanning the whole string.

There is a second multiplier. The rewrite replaces the group's closing } with the internal escClose sentinel, which is '\0CLOSE' + Math.random() + '\0' - about 25 characters. The working string therefore grows by ~25 characters on every pass:

n	input length	final string length
1,000	1,006	26,006
8,000	8,006	208,006

So the input is inflated roughly 26x, and that factor multiplies both the quadratic constant and peak memory. This makes it partly a memory-pressure issue as well as a CPU one.

Why `max` and `maxLength` do not help

The cost is in parsing, before the result set exists. The payload yields 2 results regardless of size, so neither bound is ever reached.

Impact

An application passing an untrusted pattern to expand(), directly or through minimatch / glob, can have its event loop blocked for tens of seconds by a payload well under minimatch's 65,536-character cap. For a single-threaded Node server that is a full stall, not just a slow request.

Degraded availability rather than a crash - the process recovers once the expansion completes.

Affected versions

Verified affected on 1.1.18, 2.1.4, 3.0.6 and 5.0.9, all within a few percent of each other (~460-490 ms at n=16,000).

Patch

The rewrite loop gets an iteration bound. Past the cap the remaining string is treated as non-expanding and returned literally, consistent with the existing max / maxLength caps, which truncate rather than throw.

Note this bounds the number of passes, not the cost of each: worst-case work remains proportional to cap x input length. The cap is set low enough that the residual is bounded in practice, and far above what any realistic {a},b} input needs.

Severity note

Scored 5.3 Medium (A:L) for consistency with GHSA-3jxr-9vmj-r5cp, the other algorithmic-complexity advisory on this package (CWE-407), which uses the same vector. The stack-exhaustion advisories on this package score A:H because they crash the process outright; this one stalls it.

Severity

CVSS Score: 5.3 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Release Notes

juliangruber/brace-expansion (brace-expansion@<1.1.13)

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renovate Bot commented Oct 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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

Details

Summary

Vector 1 - unbounded recursion on post

Vector 2 - push.apply with an unbounded array

Why max and maxLength do not help

Impact

Not a regression

Patch

Severity note

Credit

Severity

References

brace-expansion: DoS via uncontrolled recursion on nested brace groups causing stack exhaustion

Details

Summary

Two recursion sites

Why max and maxLength do not help

Impact

Affected versions

Patch

Severity

References

brace-expansion: Quadratic-time expansion of the {a},b} rewrite causes CPU denial of service

Details

Summary

Reproduction

Mechanism

Why max and maxLength do not help

Impact

Affected versions

Patch

Severity note

Severity

References

Release Notes

Configuration

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renovate Bot commented Oct 4, 2026 •

edited

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Vector 1 - unbounded recursion on `post`

Vector 2 - `push.apply` with an unbounded array

Why `max` and `maxLength` do not help

Why `max` and `maxLength` do not help

brace-expansion: Quadratic-time expansion of the `{a},b}` rewrite causes CPU denial of service

Why `max` and `maxLength` do not help

changeset-bot Bot commented Oct 4, 2026 •

edited

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