# RE2JS: Quadratic-time denial of service in re2js lookbehind matching Advisory record · `GHSA-gg6h-894w-4m9c` - **Identifiers:** `GHSA-gg6h-894w-4m9c` · `CVE-2026-116795` - **State:** Confirmed - **Severity:** CVSS 7.5 High - **Critical:** No - **Weakness (CWE):** [CWE-407](https://cwe.mitre.org/data/definitions/407.html) · [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html) - **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) - **Published:** 28 Oct 2026 - **Updated:** 28 Oct 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 28 Oct 2026, 21:10 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `re2js` (npm): affected `>=2.2.0, <2.8.7`; fixed in `2.8.7` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > The re2js npm package, versions 2.2.0 up to but not including 2.8.7, has a quadratic-time matching problem when the opt-in LOOKBEHINDS flag is used with repeated-matching APIs such as find loops, matchAll, split, or replaceAll. An attacker who can supply text to be matched, such as user input or uploaded logs, can cause a single call on about 16,000 characters to take tens of seconds of CPU, which can stall a Node.js process. The fix is to upgrade to re2js 2.8.7. Written 31 Oct 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0046, the 40th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 28 Oct 2026, 17:14 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-116795) - 28 Oct 2026, 18:17 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-116795) - 31 Oct 2026, 13:32 UTC: First seen by agentprime - 31 Oct 2026, 13:32 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-gg6h-894w-4m9c) ## Sources - [GitHub Advisory Database: GHSA-gg6h-894w-4m9c](https://github.com/advisories/GHSA-gg6h-894w-4m9c) - [OSV: GHSA-gg6h-894w-4m9c](https://osv.dev/vulnerability/GHSA-gg6h-894w-4m9c) - - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .