How severe is CVE-2026-109563?

CVE-2026-109563 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-109563 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-109563?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-109563 published?

CVE-2026-109563 was published on 2026-10-12 and last updated on 2026-10-16.

CVE-2026-109563

CVE-2026-109563 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Published: 2026-10-12
Last modified: 2026-10-16

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.

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.
How severe is CVE-2026-109563?: CVE-2026-109563 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-109563 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-109563?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-109563 published?: CVE-2026-109563 was published on 2026-10-12 and last updated on 2026-10-16.

References

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