Angular: Sanitization bypass via directive host bindings on concrete host elements in @angular/core and @angular/compiler

Overview

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.28, 21.2.20, and 22.1.0, Angular's compiler and runtime in @angular/core and @angular/compiler could omit or select an incorrect sanitizer for security-sensitive directive host bindings because SecurityContext was derived from the declaring directive or component selector rather than the concrete host element. The mismatch is reachable through hostDirectives composition, inherited HostBinding declarations, createComponent with a custom hostElement or dynamic directives, SVG/MathML namespace elements, and tag-neutral selectors such as :not(...). Attacker-controlled href, src, action, xlink:href, or data values can therefore reach DOM attributes without Angular's built-in sanitizer and execute arbitrary JavaScript in the user's browser context. Applications unable to upgrade can use DomSanitizer.sanitize with SecurityContext.URL before assignment or restrict inputs to validated HTTP and HTTPS URL schemes. This issue is fixed in versions 20.3.28, 21.2.20, and 22.1.0.

Affected

• angular <= 19.2.25
• angular >= 20.0.0, < 20.3.28
• angular >= 21.0.0, < 21.2.20
• angular >= 22.0.0, < 22.1.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.