Answer in brief
CVE-2026-33750 records a Medium severity (CVSS 6.5) vulnerability in brace-expansion: Zero-step sequence causes process hang and memory exhaustion. The current sources do not mark it as known exploited. The current feed maps brace-expansion (npm), brace-expansion (npm), brace-expansion (npm), brace-expansion (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps brace-expansion (npm), brace-expansion (npm), brace-expansion (npm), brace-expansion (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| brace-expansionnpm | >=4.0.0 <5.0.5 | 5.0.5 |
| brace-expansionnpm | >=3.0.0 <3.0.2 | 3.0.2 |
| brace-expansionnpm | >=2.0.0 <2.0.3 | 2.0.3 |
| brace-expansionnpm | >=0 <1.1.13 | 1.1.13 |
Published upstream
Mar 26, 2026
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Sep 10, 2026
### Impact A brace pattern with a zero step value (e.g., `{1..2..0}`) causes the sequence generation loop to run indefinitely, making the process hang for seconds and allocate heaps of memory. The loop in question: https://github.com/juliangruber/brace-expansion/blob/daa71bcb4a30a2df9bcb7f7b8daaf2ab30e5794a/src/index.ts#L184 `test()` is one of https://github.com/juliangruber/brace-expansion/blob/daa71bcb4a30a2df9bcb7f7b8daaf2ab30e5794a/src/index.ts#L107-L113 The increment is computed as `Math.abs(0) = 0`, so the loop variable never advances. On a test machine, the process hangs for about 3.5 seconds and allocates roughly 1.9 GB of memory before throwing a `RangeError`. Setting max to any value has no effect because the limit is only checked at the output combination step, not during sequence generation. This affects any application that passes untrusted strings to expand(), or by error sets a step value of `0`. That includes tools built on minimatch/glob that resolve patterns from CLI arguments or config files. The input needed is just 10 bytes. ### Patches Upgrade to versions - 5.0.5+ A step increment of 0 is now sanitized to 1, which matches bash behavior. ### Workarounds Sanitize strings passed to `expand()` to ensure a step value of `0` is not used.
Quoted source text, attributed separately from HOL analysis.