CVE-2026-8981
CVE-2026-8981 is a low-severity vulnerability with a CVSS 3.x base score of 3.5. 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-79.
Key facts
- Severity: Low (CVSS 3.x base score 3.5)
- EPSS exploit prediction: 0% (4th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-35352
- Weakness: CWE-79
- Published:
- Last modified:
Description
The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.
Frequently asked questions
- What is CVE-2026-8981?
- The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.
- How severe is CVE-2026-8981?
- CVE-2026-8981 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
- Is CVE-2026-8981 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-8981?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-8981 have an EU (EUVD) identifier?
- Yes. CVE-2026-8981 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35352.
- When was CVE-2026-8981 published?
- CVE-2026-8981 was published on 2026-06-09 and last updated on 2026-06-17.
References
Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities
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- CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
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- 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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