CVE-2026-77850: Stored XSS in AshAdmin relationship typeahead via unescaped label_field content

Severity: high (CVSS 8.4 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-31 · updated 2026-09-01
Weakness: CWE-79

Description

Stored Cross-site Scripting vulnerability in ash-project ash_admin executes attacker-supplied record content as script in an administrator's browser. The relationship typeahead components AshAdmin.Components.Resource.RelationshipField and AshAdmin.Components.Resource.ManagedRelationshipSelectField highlight the matched search term by wrapping it in <b> tags and rendering the whole string with Phoenix.HTML.raw/1. The highlighted value is the destination record's label_field, ordinary database content that is often written by lower-privileged users. Because raw/1 disables output escaping for the entire string, a stored label such as <img src=x onerror=...> runs as JavaScript in the admin's session as soon as a matching record appears in the dropdown, giving the attacker the admin's privileges over everything AshAdmin exposes. The fix HTML-escapes the label before inserting the highlight markup. This issue affects ash_admin: from 0.13.0 before 1.3.1.

Affected products

ash-project ash_admin: from 0.13.0 before 1.3.1 — fixed in 1.3.1

How to fix

Upgrade to a fixed version: ash-project ash_admin 1.3.1. Check the vendor advisory for mitigations.

References

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