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Fencer Intel
medium 6.4

CVE-2026-0894 json

Content Blocks (Custom Post Widget) <= 3.3.9 - Authenticated (Author+) Stored Cross-Site Scripting via content_block Shortcode

published 6mo ago modified 4mo ago also EUVD-2026-23670

cvss
6.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's content_block shortcode in all versions up to, and including, 3.3.9 due to insufficient input sanitization and output escaping on user supplied values consumed from user-created content blocks. 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.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6mo ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Affected products

  • vanderwijk Content Blocks (Custom Post Widget)

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.