CVE-2026-3876
CVE-2026-3876 is a high-severity vulnerability with a CVSS 3.x base score of 7.2. 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: High (CVSS 3.x base score 7.2)
- EPSS exploit prediction: 0% (19th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-23212
- Weakness: CWE-79
- Published:
- Last modified:
Description
The Prismatic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'prismatic_encoded' pseudo-shortcode in all versions up to, and including, 3.7.3. This is due to insufficient input sanitization and output escaping on user-supplied attributes within the 'prismatic_decode' function. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page by submitting a comment containing a crafted 'prismatic_encoded' pseudo-shortcode.
Frequently asked questions
- What is CVE-2026-3876?
- The Prismatic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'prismatic_encoded' pseudo-shortcode in all versions up to, and including, 3.7.3. This is due to insufficient input sanitization and output escaping on user-supplied attributes within the 'prismatic_decode' function. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page by submitting a comment containing a crafted 'prismatic_encoded' pseudo-shortcode.
- How severe is CVE-2026-3876?
- CVE-2026-3876 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
- Is CVE-2026-3876 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-3876?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-3876 have an EU (EUVD) identifier?
- Yes. CVE-2026-3876 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23212.
- When was CVE-2026-3876 published?
- CVE-2026-3876 was published on 2026-04-16 and last updated on 2026-06-17.
References
- https://plugins.trac.wordpress.org/changeset?old_path=/prismatic/tags/3.7.3/inc/prismatic-core.php&new_path=/prismatic/tags/3.7.4/inc/prismatic-core.php
- https://www.wordfence.com/threat-intel/vulnerabilities/id/aa4e18b0-f871-4476-af92-42e55aabdf93?source=cve
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