# CVE-2026-33750: brace-expansion: Zero-step sequence causes process hang and memory exhaustion

> An attacker can cause a denial of service by providing a brace pattern with a zero step value, leading to infinite loops and memory exhaustion.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 27 Mar 2026
- **Also known as:** AZL-81075, AZL-81084, CLEANSTART-2026-AE30126, CLEANSTART-2026-BZ46705, CLEANSTART-2026-CI27531, CLEANSTART-2026-GK81130, CLEANSTART-2026-GT72499, CLSA-2026-1777250307, CLSA-2026-1792233325, CLSA-2026-1792508599, DEBIAN-CVE-2026-33750, ECHO-cc54-afd5-c35f, GHSA-f886-m6hf-6m8v, MINI-26g8-w59r-wv77, MINI-2c29-p3x6-cr88, MINI-2h3q-p2fh-pc5f, MINI-3ffx-hp9r-rq3x, MINI-3wq9-r28x-48w7, MINI-483r-f24j-mjg8, MINI-4g57-hxjr-8xvj, MINI-4j93-w625-8xmf, MINI-5h92-gcmm-84mr, MINI-5vqc-q5c3-cf6f, MINI-7jvh-7g3h-hqr5, MINI-89ph-wv9c-v45g, MINI-8j5r-3chh-c9qr, MINI-9rvx-mv2x-mqh3, MINI-c2r5-j9xj-4fw2, MINI-f7w6-c5rq-486f, MINI-fg9j-g827-868g, MINI-fw7q-xg6j-5j8f, MINI-fx3v-34p8-8gmq, MINI-g64r-5q6p-x423, MINI-ghgg-rf9q-rr58, MINI-gp3x-gc2j-pwj2, MINI-gv9g-w9rv-fjrh, MINI-j43h-2hhp-qg86, MINI-jx39-c5v9-wfrg, MINI-mpq7-m5vh-x2rx, MINI-mqrw-r6vm-6xc3, MINI-p2j4-h965-4v39, MINI-p8m8-r83g-mfh3, MINI-pgm4-r82v-jm54, MINI-pj5h-hmjr-rm8c, MINI-qpg8-2v6g-j268, MINI-rhvx-hwxq-m424, MINI-rj3f-8g32-v2fj, MINI-rmc6-cp56-x7wv, MINI-v5gx-j82q-54p7, MINI-vg56-q8qv-jp28, MINI-wv75-qqx5-5gmg, OESA-2026-1835, ROOT-APP-NPM-CVE-2026-33750, UBUNTU-CVE-2026-33750

## What is CVE-2026-33750?

CVE-2026-33750 is a medium-severity denial of service vulnerability in juliangruber brace-expansion, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The brace-expansion library generates arbitrary strings containing a common prefix and suffix. Prior to versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13, 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. Versions 5.0.5, 3.0.2, 2.0.3, and 1.1.13 fix the issue. As a workaround, sanitize strings passed to `expand()` to ensure a step value of `0` is not used.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-33750?

8 open source packages ship an affected version, including brace-expansion. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `brace-expansion` | npm | All versions | 1.1.13 |
| `brace-expansion` | npm | All versions | 1.1.13 |
| `brace-expansion` | npm | From 2.0.0 | 2.0.3 |
| `brace-expansion` | npm | From 2.0.0 | 2.0.3 |
| `brace-expansion` | npm | From 3.0.0 | 3.0.2 |
| `brace-expansion` | npm | From 3.0.0 | 3.0.2 |
| `brace-expansion` | npm | From 4.0.0 | 5.0.5 |
| `brace-expansion` | npm | From 4.0.0 | 5.0.5 |

Products: Juliangruber Brace-Expansion.

## How do I fix CVE-2026-33750?

Upgrade brace-expansion to a fixed version for your release line: 1.1.13, 2.0.3, 3.0.2 or 5.0.5.

## Is CVE-2026-33750 being exploited?

There is no known exploitation of CVE-2026-33750 in the wild and no public exploit code.

## Other vulnerabilities in juliangruber brace-expansion

- [CVE-2026-69152](https://insights.sbomify.com/CVE-2026-69152/): brace-expansion: DoS via unbounded intermediate arrays, bypassing the CVE-2026-14257 mitigation (high 7.5)
- [CVE-2026-14257](https://insights.sbomify.com/CVE-2026-14257/): brace-expansion DoS via unbounded expansion length causing an out-of-memory process crash (high 7.5)
- [CVE-2026-45149](https://insights.sbomify.com/CVE-2026-45149/): brace-expansion: Large numeric range defeats documented `max` DoS protection (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33750 and fix it if it is affected.

What it is: CVE-2026-33750 is a medium-severity denial of service vulnerability in juliangruber brace-expansion, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-33750 in the wild and no public exploit code.

Affected packages and fixed versions:
- brace-expansion (npm): affected all versions; fixed in 1.1.13
- brace-expansion (npm): affected all versions; fixed in 1.1.13
- brace-expansion (npm): affected from 2.0.0; fixed in 2.0.3
- brace-expansion (npm): affected from 2.0.0; fixed in 2.0.3
- brace-expansion (npm): affected from 3.0.0; fixed in 3.0.2
- brace-expansion (npm): affected from 3.0.0; fixed in 3.0.2
- brace-expansion (npm): affected from 4.0.0; fixed in 5.0.5
- brace-expansion (npm): affected from 4.0.0; fixed in 5.0.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33750/ (Markdown: https://insights.sbomify.com/CVE-2026-33750/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33750
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33750
- OSV: https://osv.dev/vulnerability/CVE-2026-33750

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33750/
Summaries are generated and may contain mistakes; the official description above is the record.