CVE-2026-82731

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-01 03:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-01 21:15 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 2.3 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-01 03:16 UTC

Last modified

2026-09-01 21:15 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-601

Record status

Deferred

Attack profile CVSS 4.0 · 2.3

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Passive

Confidentiality

Low

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-82731.md and follow it. Check whether this project is affected by CVE-2026-82731. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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