How severe is CVE-2026-8866?

CVE-2026-8866 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-8866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-8866?

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

Does CVE-2026-8866 have an EU (EUVD) identifier?

Yes. CVE-2026-8866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32069.

When was CVE-2026-8866 published?

CVE-2026-8866 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2026-8866

CVE-2026-8866 is a medium-severity vulnerability with a CVSS 3.x base score of 6.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32069
Weakness: CWE-79
Published: 2026-05-27
Last modified: 2026-06-17

Description

The jQuery googleslides plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'googleslides' shortcode in all versions up to, and including, 1.3. This is due to insufficient input sanitization and output escaping on user supplied attributes (userid, albumid, authkey, imgmax, maxresults, random, caption, albumlink, time, and fadespeed) in the googleslides_handler() function, which interpolates the attribute values directly into single-quoted HTML attributes without using esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Frequently asked questions

What is CVE-2026-8866?: The jQuery googleslides plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'googleslides' shortcode in all versions up to, and including, 1.3. This is due to insufficient input sanitization and output escaping on user supplied attributes (userid, albumid, authkey, imgmax, maxresults, random, caption, albumlink, time, and fadespeed) in the googleslides_handler() function, which interpolates the attribute values directly into single-quoted HTML attributes without using esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
How severe is CVE-2026-8866?: CVE-2026-8866 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-8866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-8866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-8866 have an EU (EUVD) identifier?: Yes. CVE-2026-8866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32069.
When was CVE-2026-8866 published?: CVE-2026-8866 was published on 2026-05-27 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

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CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

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