Answer in brief
CVE-2026-81315 records a High severity (CVSS 7.4) vulnerability in MCP DNS-rebinding origin check in AshAi is bypassed by a spoofed X-Forwarded-Proto header. The current sources do not mark it as known exploited. The current feed maps ash-project/ash_ai (generic), ash-project/ash_ai (generic), ash-project/ash-project/ash_ai (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps ash-project/ash_ai (generic), ash-project/ash_ai (generic), ash-project/ash-project/ash_ai (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| ash-project/ash_aigeneric | >=c94f0b17fbe252f68755ba512678586164ba6139 <28af68d73134df0b8fb3aa6ab03e8fd795b07c21 | 28af68d73134df0b8fb3aa6ab03e8fd795b07c21 |
| ash-project/ash_aigeneric | >=0.8.0 <1.0.0 | 1.0.0 |
| ash-project/ash-project/ash_aigeneric | >=c94f0b17fbe252f68755ba512678586164ba6139 <28af68d73134df0b8fb3aa6ab03e8fd795b07c21 | 28af68d73134df0b8fb3aa6ab03e8fd795b07c21 |
Published upstream
Aug 31, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 31, 2026
Origin Validation Error vulnerability in ash-project ash_ai allows a malicious web page to bypass the MCP server's DNS-rebinding protection and issue cross-site requests to a user's local MCP server with that user's actor. In AshAi.Mcp.Server, with the default allowed_origins: nil, origin_allowed?/3 accepts an origin when uri.host == conn.host and the forwarded scheme is https. Both values are attacker-controlled: conn.host comes from the Host header and the scheme is read from the raw x-forwarded-proto header with no trusted-proxy check. Under DNS rebinding the browser sends the attacker's origin and a matching host, and page JavaScript may set X-Forwarded-Proto: https, so the check passes with no TLS or proxy involved. The fix trusts only localhost origins by default; other origins require an explicit allowed_origins allowlist. This issue affects ash_ai: from 0.8.0 before 1.0.0.
Quoted source text, attributed separately from HOL analysis.