CVE-2026-88058 Angular: SSR XSS via Unescaped Processing Instruction (<?...?>) Nodes in Fallback Raw-Content Elements
Angular SSR fails to escape processing instructions in raw-content elements, allowing attackers to inject scripts and execute arbitrary JavaScript in victim browsers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-88058?
CVE-2026-88058 is a high-severity cross-site scripting vulnerability in angular, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.30, 21.2.22, and 22.1.4, Angular server-side rendering (SSR) in @angular/platform-server serializes ProcessingInstruction DOM nodes inside fallback raw-content elements without escaping matching ancestor closing tags. ProcessingInstruction data escaped greater-than characters but left less-than characters untouched and did not inspect fallback ancestors, so data such as a matching closing tag prematurely terminates noscript, iframe, noembed, or noframes containers. The vulnerable nodes cannot be authored through standard Angular templates; reachability requires application or library code using inject(DOCUMENT).createProcessingInstruction with attacker-controlled data or Renderer2 DOM insertion inside a fallback container. In HTML5 RAWTEXT parsing, the premature close causes subsequent sibling elements to be interpreted as live HTML and enables arbitrary JavaScript execution in a victim's browser. This issue is fixed in versions 20.3.30, 21.2.22, and 22.1.4.
Which versions are affected by CVE-2026-88058?
8 open source packages ship an affected version, including @angular/platform-server. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@angular/platform-server npm | All versions to 19.2.25 | None |
@angular/platform-server npm | All versions to 19.2.25 | None |
@angular/platform-server npm | From 20.0.0 | 20.3.30 |
@angular/platform-server npm | From 20.0.0 | 20.3.30 |
@angular/platform-server npm | From 21.0.0 | 21.2.22 |
@angular/platform-server npm | From 21.0.0 | 21.2.22 |
2 more packages
@angular/platform-server npm | From 22.0.0 | 22.1.4 |
@angular/platform-server npm | From 22.0.0 | 22.1.4 |
Products include Angular Angular.
How do I fix CVE-2026-88058?
Upgrade @angular/platform-server to a fixed version for your release line: 20.3.30, 21.2.22 or 22.1.4.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-88058 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88058 exists.
Other vulnerabilities in angular
- CVE-2026-68945 Angular: Cache-Key Ambiguity in HttpTransferCache Leading to Cross-Request Response Reuse and State Poisoning
- CVE-2026-46417 Angular: SSRF via Hostname Hijacking in @angular/platform-server
- CVE-2026-50168 Angular: URL Parser Differential in @angular/platform-server leading to SSRF Allowlist Bypass
- CVE-2026-54266 Angular: Weak 32-Bit Cache Key Hashing in `HttpTransferCache` Leading to Cross-Request Data Leakage and State Poisoning
- CVE-2026-41423 Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server
Sources
Also known as DEBIAN-CVE-2026-88058, GHSA-j3r3-mxqp-r2p4, UBUNTU-CVE-2026-88058.