Answer in brief
CVE-2026-50555 records a High severity (CVSS 8.6) vulnerability in Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in @angular/platform-server. The current sources do not mark it as known exploited. The current feed maps @angular/platform-server (npm), @angular/platform-server (npm), @angular/platform-server (npm), @angular/platform-server (npm) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps @angular/platform-server (npm), @angular/platform-server (npm), @angular/platform-server (npm), @angular/platform-server (npm) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| @angular/platform-servernpm | >=22.0.0-next.0,<22.0.0-rc.2 | 22.0.0-rc.2 |
| @angular/platform-servernpm | >=21.0.0-next.0,<21.2.16 | 21.2.16 |
| @angular/platform-servernpm | >=20.0.0-next.0,<20.3.24 | 20.3.24 |
| @angular/platform-servernpm | >=19.0.0-next.0,<19.2.25 | 19.2.25 |
| @angular/platform-servernpm | <=18.2.14 | Not reported |
| @angular/platform-servernpm | >=22.0.0-next.0<22.0.0-rc.2 | Not reported |
| @angular/platform-servernpm | >=21.0.0-next.0<21.2.16 | Not reported |
| @angular/platform-servernpm | >=20.0.0-next.0<20.3.24 | Not reported |
| @angular/platform-servernpm | >=19.0.0-next.0<19.2.25 | Not reported |
Published upstream
Jun 2, 2026
Evidence: source:ghsa:source_dates:source-dates:recordSource modified
Jul 15, 2026
Evidence: source:ghsa:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
A Cross-Site Scripting (XSS) vulnerability exists in `@angular/platform-server`'s DOM emulation dependency (`domino`) when serializing the content of raw-text elements (such as `<script>`, `<style>`, and `<iframe>`). `domino` supports escaping raw-text elements during serialization to prevent closing-tag breakout. However, a **Unicode index alignment bug** existed in this escaping logic. In JavaScript, string lengths and character indices are calculated based on UTF-16 code units (where astral characters—such as emojis—occupy 2 code units / 4 bytes). If the bound dynamic text contained astral Unicode characters _before_ the closing tag (e.g. `</script>`, `</style>`, or `</iframe>`), the index offset calculation in `domino`'s replacement logic shifted. This misalignment caused `domino` to fail to replace or escape the closing tag, leaving it raw and unescaped in the output HTML. An attacker who controls the dynamic text can supply a payload containing both an astral Unicode character and a closing tag (e.g., `😀</iframe><script>alert(1)</script>`). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent `<script>` block, leading to same-origin Cross-Site Scripting (XSS). ### Impact This vulnerability allows an attacker to perform same-origin Cross-Site Scripting (XSS) attacks against any user visiting an SSR-rendered page that binds user-controlled data inside raw-text elements. This can lead to session hijacking, credentials theft, unauthorized actions on behalf of users, and defacement. ### Patched Versions - 22.0.0-rc.2 - 21.2.16 - 20.3.24 - 19.2.25 ### Workarounds If you cannot immediately update your dependencies, you can: - Avoid binding user-controlled values inside `<iframe>` or other raw-text elements. - Sanitize any user input placed inside raw-text elements to explicitly strip closing tags before passing it to the template. ### References - https://github.com/angular/domino/pull/29
Quoted source text, attributed separately from HOL analysis.