CVE-2026-82731: CWE-601 URL Redirection to Untrusted Site ('Open Redirect') in ash-project ash_typescript
Description
URL Redirection to Untrusted Site ('Open Redirect') vulnerability in ash-project ash_typescript allows an attacker who controls a path-parameter value to redirect a generated client's request, and the credentials attached to it, to an unintended route or an external origin. The URL builders in lib/ash_typescript/typed_controller/codegen/route_renderer.ex replace each :param placeholder with a bare template interpolation and never call encodeURIComponent, so the value reaches executeTypedControllerRequest raw. A value containing ../ is normalised away by the fetch URL resolver and reaches a different route, while ? or # truncates the path and can smuggle or override query parameters. For a route whose path begins with a parameter, a value such as /evil.example.com/x yields the protocol-relative URL //evil.example.com/x, sending the request and the credentials from TypedControllerConfig to an attacker-controlled host. Nothing constrains the value at runtime: get_path_param_type/2 emits only a TypeScript type, which is erased. The query-string path is unaffected, since URLSearchParams.set encodes its own values. This issue affects ash_typescript: from 0.15.0 before 0.18.0.
CVSS v4.0
Score 2.3low
Affected software
ash-project
ash_typescript
ash-project
ash_typescript
cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in ash_typescript occurs because the URL builders in lib/ash_typescript/typed_controller/codegen/route_renderer.ex replace :param placeholders with raw template interpolation without encoding. This allows an attacker to supply path parameter values that can manipulate the final URL, including protocol-relative URLs that redirect requests and credentials to attacker-controlled hosts. The issue affects versions >=0.15.0 and <0.18.0. Query-string parameters are not affected due to proper encoding by URLSearchParams.set. No official remediation or patch is currently documented.
Potential Impact
An attacker who can control a path parameter can redirect client requests, including attached credentials, to an unintended or external origin. This could lead to credential leakage or redirection to malicious sites. However, the impact is limited by the low CVSS score and the requirement for user interaction (UI:P). There is no indication of active exploitation in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid using untrusted input in path parameters or implement manual encoding of path parameters to prevent injection of protocol-relative URLs or path traversal sequences.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- EEF
- Date Reserved
- 2026-08-31T00:59:08.960Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a963a79acd9273b491bc8c7
Added to database: 09/01/2026, 02:37:45 UTC
Last enriched: 09/07/2026, 14:46:16 UTC
Last updated: 10/15/2026, 18:48:24 UTC
Views: 77
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