CVE-2026-109563 (CVSS 7.5)

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0035

Probability of exploitation

0.27%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-1333 CWE-1333

References

Other References

https://github.com/rdfjs/N3.js https://github.com/rdfjs/N3.js/commit/b1c497fddb02c4772d61916bd2634115f45f424d https://github.com/rdfjs/N3.js/pull/760 https://www.vulncheck.com/advisories/n3-js-before-2.11.1-redos-via-n3lexer-numeric-literal-regex

Frequently Asked Questions

What is CVE-2026-109563? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-109563? +

CVE-2026-109563 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0035, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-109563? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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