CVE-2026-27739
CRITICALAngular CLI <21.2.0-rc.1, 21.0.0-21.1.4, 20.0.0-20.3.16, <19.2.21 - SSRF via Unvalidated Headers
Title source: llmExploitation Summary
EIP tracks 4 public exploits for CVE-2026-27739. PoCs published by XiaomingX, adminlove520, mr-redoo7.
AI-analyzed exploit summary This repository contains a functional Python exploit for CVE-2026-27739, targeting Angular Universal SSR applications with SSRF and header injection vulnerabilities. The exploit demonstrates SSRF via unsanitized headers and prototype pollution, with automated testing for AWS/GCP metadata endpoints and local services.
Description
The Angular SSR is a server-rise rendering tool for Angular applications. Versions prior to 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 have a Server-Side Request Forgery (SSRF) vulnerability in the Angular SSR request handling pipeline. The vulnerability exists because Angular’s internal URL reconstruction logic directly trusts and consumes user-controlled HTTP headers specifically the Host and `X-Forwarded-*` family to determine the application's base origin without any validation of the destination domain. Specifically, the framework didn't have checks for the host domain, path and character sanitization, and port validation. This vulnerability manifests in two primary ways: implicit relative URL resolution and explicit manual construction. When successfully exploited, this vulnerability allows for arbitrary internal request steering. This can lead to credential exfiltration, internal network probing, and a confidentiality breach. In order to be vulnerable, the victim application must use Angular SSR (Server-Side Rendering), the application must perform `HttpClient` requests using relative URLs OR manually construct URLs using the unvalidated `Host` / `X-Forwarded-*` headers using the `REQUEST` object, the application server must be reachable by an attacker who can influence these headers without strict validation from a front-facing proxy, and the infrastructure (Cloud, CDN, or Load Balancer) must not sanitize or validate incoming headers. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 contain a patch. Some workarounds are available. Avoid using `req.headers` for URL construction. Instead, use trusted variables for base API paths. Those who cannot upgrade immediately should implement a middleware in their `server.ts` to enforce numeric ports and validated hostnames.
Exploits (4)
This repository contains a functional Python exploit for CVE-2026-27739, targeting Angular Universal SSR applications with SSRF and header injection vulnerabilities. The exploit demonstrates SSRF via unsanitized headers and prototype pollution, with automated testing for AWS/GCP metadata endpoints and local services.
This repository contains a functional Python exploit for CVE-2026-27739, targeting Angular Universal SSR applications with SSRF and header injection vulnerabilities. The exploit demonstrates SSRF via unsanitized headers and attempts to extract sensitive data from cloud metadata services.
This repository contains a functional Python exploit for CVE-2026-27739, targeting Angular Universal SSR applications with SSRF and header injection vulnerabilities. The PoC demonstrates SSRF via unsanitized headers and prototype pollution, with automated testing for AWS/GCP metadata endpoints and local services.
This repository contains a functional Python exploit for CVE-2026-27739, targeting Angular Universal SSR applications vulnerable to SSRF and header injection via unsanitized X-Forwarded-* headers. The PoC demonstrates SSRF to internal services (AWS IMDS, GCP metadata) and header manipulation through prototype pollution.
References (4)
Scores
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N