CVE-2026-28222: Wagtail: Improper escaping of HTML (Cross-site Scripting) on TableBlock class attributes

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-05 · updated 2026-06-17
Weakness: CWE-79

Description

Wagtail is an open source content management system built on Django. Prior to versions 6.3.8, 7.0.6, 7.2.3, and 7.3.1, a stored cross-site scripting (XSS) vulnerability exists on rendering TableBlock blocks within a StreamField. A user with access to create or edit pages containing TableBlock StreamField blocks is able to set specially-crafted class attributes on the block which run arbitrary JavaScript code when the page is viewed. When viewed by a user with higher privileges, this could lead to performing actions with that user's credentials. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin, and only affects sites using TableBlock. This issue has been patched in versions 6.3.8, 7.0.6, 7.2.3, and 7.3.1.

Affected products

wagtail: before 6.3.8; from 6.4 before 7.0.6; from 7.1 before 7.2.3; 7.3, 7.3-rc1 — fixed in 6.3.8, 7.0.6, 7.2.3

How to fix

Upgrade to a fixed version: wagtail 6.3.8, 7.0.6, 7.2.3. Check the vendor advisory for mitigations.

References

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