# CVE-2026-109563: N3.js before 2.11.1 ReDoS via N3Lexer Numeric-Literal Regex

> Attackers can cause denial of service in applications using N3.js by supplying crafted Turtle or N3 input with long digit runs, blocking the Node.js event loop.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-109563, GHSA-xf53-x4jg-3wwc, UBUNTU-CVE-2026-109563

## What is CVE-2026-109563?

CVE-2026-109563 is a high-severity denial of service vulnerability in rdfjs N3.js, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

N3.js before 2.11.1 contains a regular expression denial of service vulnerability in the N3Lexer number pattern that backtracks quadratically on long digit runs. Attackers can supply untrusted Turtle or N3 input containing long runs of digits that do not end a number, blocking the Node.js event loop and causing denial of service.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-109563?


## How do I fix CVE-2026-109563?

No fix has been published for CVE-2026-109563 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109563 being exploited?

There is no known exploitation of CVE-2026-109563 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109563 and fix it if it is affected.

What it is: CVE-2026-109563 is a high-severity denial of service vulnerability in rdfjs N3.js, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-109563 in the wild and no public exploit code.

Affected product: rdfjs N3.js. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-109563/ (Markdown: https://insights.sbomify.com/CVE-2026-109563/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109563
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109563
- OSV: https://osv.dev/vulnerability/CVE-2026-109563

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109563/
Summaries are generated and may contain mistakes; the official description above is the record.