CVE-2026-109563
ReDoS in N3.js lexer can block Node.js event loop via long digit runs
Is CVE-2026-109563 being exploited?
Not confirmed. CVE-2026-109563 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.35% probability of exploitation in the next 30 days.
How severe is CVE-2026-109563?
CVE-2026-109563 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-109563?
Yes. A fix has been recorded for CVE-2026-109563. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-109563 affect?
CVE-2026-109563 affects N3.js < 2.11.1, Node.js applications using N3.js, RDF/N3/Turtle parsers. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-109563?
Upgrade N3.js to >=2.11.1 and validate/limit untrusted input size
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote denial of service: crafted Turtle/N3 with long digit runs triggers quadratic regex backtracking, blocking the Node.js event loop and causing service outage.
Patch when possible
- affected< 2.11.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.