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.
CVE-2026-109563
HIGHPre-NVD 7.57.5Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-10-12. The CNA's CVSS baseline 7.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory
7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHhigh confidence
- EG Risk
- 49EG Risk 49/100
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computed (value × EchelonGraph’s weight)Severity75% × 45%The EG Score, 7.5 of 10.Exploitation0.4% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.4%
- EPSS %ILE
- 26th
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
October 12, 2026
Last Modified
October 14, 2026
Advisory Details (4)
Auto-updated Oct 12, 2026Patch available. Sources: github_commit, github_pr.
Web page
N3.js before 2.11.1 ReDoS via N3Lexer Numeric-Literal Regex | Advisories | VulnCheck
https://www.vulncheck.com/advisories/n3-js-before-2.11.1-redos-via-n3lexer-numeric-literal-regexGitHub pull request Patch Available
fix: make number, base IRI and relative IRI matching linear
Patch available: rdfjs/N3.js v3.0.0-alpha.1 (PR #760 merged 2026-10-04)
https://github.com/rdfjs/N3.js/pull/760GitHub commit Patch Available
commit b1c497fddb02 (rdfjs/N3.js)
Patch available: rdfjs/N3.js v3.0.0-alpha.1 (contains commit b1c497fddb02)
https://github.com/rdfjs/N3.js/commit/b1c497fddb02c4772d61916bd2634115f45f424dWeb page
GitHub - rdfjs/N3.js: Lightning fast, spec-compatible, streaming RDF for JavaScript · GitHub
https://github.com/rdfjs/N3.jsVendor Advisories for CVE-2026-109563(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-14 11:40 UTCEG score recompute
- 2026-10-14 11:40 UTCGHSA enrichmentGHSA-xf53-x4jg-3wwc · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 26th percentile
- 2026-10-12 21:26 UTCEG score recompute
- 2026-10-12 21:02 UTCEG score recomputeFirst assessed: 7.5 HIGH
- 2026-10-12 20:59 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-109563?
CVE-2026-109563 is a high-severity vulnerability; its CVE record was published on October 12, 2026. 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…
When was CVE-2026-109563 made public?
CVE-2026-109563 was made public on October 4, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 12, 2026. EchelonGraph's copy of the record carries a last-modified date of October 14, 2026; the record at its source may have been updated since.
Is CVE-2026-109563 actively exploited?
CVE-2026-109563 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (26th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-109563?
CVE-2026-109563 has a CVSS base score of 7.5 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-109563?
A fix for CVE-2026-109563 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-109563 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-109563
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