chore(deps): update dependency brace-expansion@>=4.0.0 <5.0.9 to ^5.0.12 [security] - #1244
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This PR contains the following updates:
^5.0.9→^5.0.12](https://renovatebot.com/diffs/npm/brace-expansion@>=4.0.0 <5.0.9/5.0.9/5.0.12)Warning
Some dependencies could not be looked up. Check the Dependency Dashboard for more information.
brace-expansion: Quadratic-time expansion of the
{a},b}rewrite causes CPU denial of serviceCVE-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, sontrailing braces costnfull passes.Reproduction
ms/n^2is flat at ~1.7 and each doubling ofncosts 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 + 1times, once per literal}, each re-scanning the whole string.There is a second multiplier. The rewrite replaces the group's closing
}with the internalescClosesentinel, which is'\0CLOSE' + Math.random() + '\0'- about 25 characters. The working string therefore grows by ~25 characters on every pass: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
maxandmaxLengthdo not helpThe 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 throughminimatch/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/maxLengthcaps, 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 scoreA:Hbecause they crash the process outright; this one stalls it.Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Release Notes
juliangruber/brace-expansion (brace-expansion@>=4.0.0 <5.0.9)
v5.0.12Compare Source
v5.0.11Compare Source
v5.0.10Compare Source
Configuration
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