How severe is CVE-2026-5266?

CVE-2026-5266 has a CVSS 4.0 base score of 2.3, rated low severity.

Is CVE-2026-5266 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-5266?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5266 have an EU (EUVD) identifier?

Yes. CVE-2026-5266 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29157.

When was CVE-2026-5266 published?

CVE-2026-5266 was published on 2026-05-11 and last updated on 2026-06-17.

CVE-2026-5266

CVE-2026-5266 is a low-severity vulnerability with a CVSS 4.0 base score of 2.3. 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-200.

Key facts

Severity: Low (CVSS 4.0 base score 2.3)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29157
Weakness: CWE-200
Published: 2026-05-11
Last modified: 2026-06-17

Description

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation Echo. This vulnerability is associated with program files includes/Api/ApiEchoNotifications.Php. This issue affects Echo: from * before 1.43.7, 1.44.4, 1.45.2.

Frequently asked questions

What is CVE-2026-5266?: Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation Echo. This vulnerability is associated with program files includes/Api/ApiEchoNotifications.Php. This issue affects Echo: from * before 1.43.7, 1.44.4, 1.45.2.
How severe is CVE-2026-5266?: CVE-2026-5266 has a CVSS 4.0 base score of 2.3, rated low severity.
Is CVE-2026-5266 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5266?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5266 have an EU (EUVD) identifier?: Yes. CVE-2026-5266 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29157.
When was CVE-2026-5266 published?: CVE-2026-5266 was published on 2026-05-11 and last updated on 2026-06-17.

References

https://phabricator.wikimedia.org/T420154

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