How severe is CVE-2026-40959?

CVE-2026-40959 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40959 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40959?

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

Does CVE-2026-40959 have an EU (EUVD) identifier?

Yes. CVE-2026-40959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23149.

When was CVE-2026-40959 published?

CVE-2026-40959 was published on 2026-04-16 and last updated on 2026-06-17.

CVE-2026-40959

CVE-2026-40959 is a critical-severity vulnerability with a CVSS 3.x base score of 9.3. 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-829.

Key facts

Severity: Critical (CVSS 3.x base score 9.3)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23149
Weakness: CWE-829
Published: 2026-04-16
Last modified: 2026-06-17

Description

Luanti 5 before 5.15.2, when LuaJIT is used, allows a Lua sandbox escape via a crafted mod.

Frequently asked questions

What is CVE-2026-40959?: Luanti 5 before 5.15.2, when LuaJIT is used, allows a Lua sandbox escape via a crafted mod.
How severe is CVE-2026-40959?: CVE-2026-40959 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40959 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40959?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-40959 have an EU (EUVD) identifier?: Yes. CVE-2026-40959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23149.
When was CVE-2026-40959 published?: CVE-2026-40959 was published on 2026-04-16 and last updated on 2026-06-17.

References

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