How severe is CVE-2026-40621?

CVE-2026-40621 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40621 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40621?

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-2026-40621 have an EU (EUVD) identifier?

Yes. CVE-2026-40621 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29940.

When was CVE-2026-40621 published?

CVE-2026-40621 was published on 2026-05-13 and last updated on 2026-06-17.

CVE-2026-40621

CVE-2026-40621 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. 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-288.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.3
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29940
Weakness: CWE-288
Published: 2026-05-13
Last modified: 2026-06-17

Description

ELECOM wireless LAN access point devices do not require authentication to access some specific URLs. The affected product may be operated without authentication.

Frequently asked questions

What is CVE-2026-40621?: ELECOM wireless LAN access point devices do not require authentication to access some specific URLs. The affected product may be operated without authentication.
How severe is CVE-2026-40621?: CVE-2026-40621 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40621 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40621?: 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-2026-40621 have an EU (EUVD) identifier?: Yes. CVE-2026-40621 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29940.
When was CVE-2026-40621 published?: CVE-2026-40621 was published on 2026-05-13 and last updated on 2026-06-17.

References

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