Quick answers
- Is CVE-2026-81315 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-81315 being exploited in the wild.
- How severe is CVE-2026-81315?
- Informational severity, published 31 August 2026.
- Which products and versions are affected?
- Ash-Project Ash Ai 0.8.0 before 1.0.0.
- Is there a fix for CVE-2026-81315?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-81315 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-81315?
- Check whether you run Ash-Project Ash Ai at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an origin validation error in AshAi.Mcp.Server's origin_allowed?/3 function. With default configuration (allowed_origins: nil), the check compares uri.host against conn.host and validates the forwarded scheme is https, but both values are attacker-controlled: the Host header and raw X-Forwarded-Proto header are used without verifying a trusted proxy. Under DNS rebinding, an attacker's origin and matching host are sent by the browser, and JavaScript can set X-Forwarded-Proto: https, causing the validation to pass even without actual TLS or proxy involvement. The fix restricts default origins to localhost only, requiring explicit allowlist configuration for other origins.
Affected products
- ash-project ash_ai 0.8.0 before 1.0.0
Timeline
- 2026-08-31: disclosed