CVE-2026-50557
CVE-2026-50557 is a Cross-site Scripting (XSS) vulnerability in @angular/core. O3 Security confirms whether CVE-2026-50557 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Angular: Template and Attribute Namespace Sanitization Bypass (XSS)
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@angular/corenpmDescription
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.15, 20.3.22 and 19.2.22, an issue in the @angular/compiler and @angular/core packages allows bypassing element and attribute sanitization/validation through specific namespace workarounds. Specifically, namespaced script elements (e.g., svg:script or <:svg:script>) were not properly identified as script elements by the Angular template preparser, allowing them to pass through template compilation without being stripped. Furthermore, security context schema mappings for element attributes did not consistently handle attributes within namespaced elements (like SVG and MathML), opening up gaps where malicious namespaced attributes could bypass runtime and compile-time sanitizers. Combined, these flaws enable an attacker who can inject or supply a template/tag structure with custom namespaces to bypass Angular's script-stripping logic and attribute sanitizers, leading to client-side Cross-Site Scripting (XSS). This vulnerability is fixed in 22.0.0-rc.2, 21.2.15, 20.3.22 and 19.2.22.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/core | ≥ 21.0.0-next.0&&< 21.2.15 | 21.2.15 |
| 📦npm | @angular/core | ≥ 22.0.0-next.0&&< 22.0.0-rc.2 | 22.0.0-rc.2 |
| 📦npm | @angular/core | ≥ 20.0.0-next.0&&< 20.3.22 | 20.3.22 |
| 📦npm | @angular/core | ≥ 19.0.0-next.0&&< 19.2.22 | 19.2.22 |
| 📦npm | @angular/core | all versions | No fix |
| 📦npm | @angular/compiler | ≥ 21.0.0-next.0&&< 21.2.15 | 21.2.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @angular/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @angular/core to 21.2.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50557 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-50557 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-50557. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-50557 in your dependencies?
O3 detects CVE-2026-50557 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.