Path Traversal in @angular/ssr (CVE-2026-44437)
Summary
Path traversal in @angular/ssr (CVE-2026-44437). Risk of unauthorized operations or information disclosure. Exploitable via redirectTo. Mitigation: upgrade to 19.2.25 or later.
Original description
The description as published by the source.
Description
A vulnerability exists in the X-Forwarded-Prefix header processing logic within Angular SSR. The internal validation mechanism fails to properly account for URL-encoded characters, specifically dots (%2e%2e). This allows an attacker to bypass security filters by injecting encoded path traversal sequences that are later decoded and utilized by the application logic.
When an Angular SSR application is configured to trust proxy headers and is deployed behind a proxy that forwards the X-Forwarded-Prefix header without prior sanitization, an attacker can provide a payload such as /%2e%2e/evil.
The vulnerability manifests in two ways:
- Open Redirect: The application processes a redirect (e.g., router
redirectTo). The decoded traversal payload manipulates the Location header, forcing the browser to an unintended path or external domain. - Server-Side Request Steering: The manipulated prefix is used as the base path for server-side
HttpClientrequests. This causes the server to make requests to unintended internal paths or external endpoints.
Attack Preconditions
- The application must use Angular SSR.
- The application must perform internal redirects or use relative URLs in server-side
HttpClientrequests. - The upstream infrastructure (Reverse Proxy/CDN) must pass the
X-Forwarded-Prefixheader to the SSR process without stripping or sanitizing it.
Workarounds
Until the patch is applied, developers should manually sanitize the `X-Forwarded…
Source: NIST National Vulnerability Database 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-2026-44437 has been found in @angular/ssr.
Attackers can target a specific entry point like redirectTo over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: upgrade @angular/ssr to 19.2.25 or later.
If unsure, ask your IT team or search "@angular/ssr CVE-2026-44437" on the vendor's site.
CVE-2026-44437 (@angular/ssr) — CWE-22 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: redirectTo / HttpClient / server.ts
Patched: 19.2.25 — apply immediately
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.
Path traversal (CWE-22) exists in @angular/ssr. Attackers reach the vulnerable code path via redirectTo without authentication.
Check the vendor advisory for the affected versions of @angular/ssr. Attack surface: redirectTo / HttpClient / server.ts.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to 19.2.25.
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/ssr' . 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/ssr' . | 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/ssrを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @angular/ssr to 19.2.25ステージング環境で 19.2.25 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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
References
- advisory nvd.nist.gov
- package github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web angular.dev
- web github.com