Cross-Site Scripting (XSS) in @angular/platform-server (CVE-2026-50555)
Summary
Cross-site scripting in @angular/platform-server (CVE-2026-50555). Risk of unauthorized operations or information disclosure. Exploitable via domino.
Original description
The description as published by the source.
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 , , and ``).
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. , , or ``), 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., 😀alert(1)). When serialized on the server during SSR, the browser parses the unescaped closing tag, exits the raw-text context early, and executes the subsequent `` 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 beh…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-50555 has been found in @angular/platform-server.
Attackers can target a specific entry point like domino over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "@angular/platform-server CVE-2026-50555" on the vendor's site.
CVE-2026-50555 (@angular/platform-server) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: domino
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in @angular/platform-server. Attackers reach the vulnerable code path via domino without authentication.
Check the vendor advisory for the affected versions of @angular/platform-server. Attack surface: domino.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@angular/platform-server' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@angular/platform-server' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@angular/platform-serverを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-50555 angular.js
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com