{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-81315", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-08-30T20:00:01.860Z", "datePublished": "2026-08-31T00:57:55.910Z", "dateUpdated": "2026-08-31T00:57:55.910Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.AshAi.Mcp.Server'"], "packageName": "ash_ai", "packageURL": "pkg:hex/ash_ai", "product": "ash_ai", "programFiles": ["lib/ash_ai/mcp/server.ex"], "programRoutines": [{"name": "'Elixir.AshAi.Mcp.Server':check_origin/2"}, {"name": "'Elixir.AshAi.Mcp.Server':origin_allowed?/3"}], "repo": "https://github.com/ash-project/ash_ai", "vendor": "ash-project", "versions": [{"lessThan": "1.0.0", "status": "affected", "version": "0.8.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.AshAi.Mcp.Server'"], "packageName": "ash-project/ash_ai", "packageURL": "pkg:github/ash-project/ash_ai", "product": "ash_ai", "programFiles": ["lib/ash_ai/mcp/server.ex"], "programRoutines": [{"name": "'Elixir.AshAi.Mcp.Server':check_origin/2"}, {"name": "'Elixir.AshAi.Mcp.Server':origin_allowed?/3"}], "repo": "https://github.com/ash-project/ash_ai", "vendor": "ash-project", "versions": [{"lessThan": "28af68d73134df0b8fb3aa6ab03e8fd795b07c21", "status": "affected", "version": "c94f0b17fbe252f68755ba512678586164ba6139", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.0.0", "versionStartIncluding": "0.8.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Peter Ullrich"}, {"lang": "en", "type": "reporter", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Zach Daniel / Ash Project"}, {"lang": "en", "type": "coordinator", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>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.</p>\n<p>In <code>AshAi.Mcp.Server</code>, with the default <code>allowed_origins: nil</code>, <code>origin_allowed?/3</code> accepts an origin when <code>uri.host == conn.host</code> and the forwarded scheme is <code>https</code>. Both values are attacker-controlled: <code>conn.host</code> comes from the <code>Host</code> header and the scheme is read from the raw <code>x-forwarded-proto</code> 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 <code>X-Forwarded-Proto: https</code>, so the check passes with no TLS or proxy involved. The fix trusts only localhost origins by default; other origins require an explicit <code>allowed_origins</code> allowlist.</p>\n<p>This issue affects ash_ai: from 0.8.0 before 1.0.0.</p>"}, {"base64": false, "type": "text/markdown", "value": "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.\n\nIn `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.\n\nThis issue affects ash_ai: from 0.8.0 before 1.0.0."}], "value": "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.\n\nIn 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.\n\nThis issue affects ash_ai: from 0.8.0 before 1.0.0."}], "impacts": [{"capecId": "CAPEC-62", "descriptions": [{"lang": "en", "value": "CAPEC-62 Cross Site Request Forgery"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 7.4, "baseSeverity": "HIGH", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-346", "description": "CWE-346 Origin Validation Error", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-08-31T00:57:55.910Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/ash-project/ash_ai/security/advisories/GHSA-c92r-f3rr-q49h"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-81315.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-81315"}, {"tags": ["patch"], "url": "https://github.com/ash-project/ash_ai/commit/28af68d73134df0b8fb3aa6ab03e8fd795b07c21"}], "source": {"discovery": "EXTERNAL"}, "title": "MCP DNS-rebinding origin check in AshAi is bypassed by a spoofed X-Forwarded-Proto header"}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.AshAi.Mcp.Server'"], "packageName": "ash_ai", "packageURL": "pkg:hex/ash_ai", "product": "ash_ai", "programFiles": ["lib/ash_ai/mcp/server.ex"], "programRoutines": [{"name": "'Elixir.AshAi.Mcp.Server':check_origin/2"}, {"name": "'Elixir.AshAi.Mcp.Server':origin_allowed?/3"}], "repo": "https://github.com/ash-project/ash_ai", "vendor": "ash-project", "versions": [{"lessThan": "1.0.0", "status": "affected", "version": "0.8.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:ash-project:ash_ai:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["'Elixir.AshAi.Mcp.Server'"], "packageName": "ash-project/ash_ai", "packageURL": "pkg:github/ash-project/ash_ai", "product": "ash_ai", "programFiles": ["lib/ash_ai/mcp/server.ex"], "programRoutines": [{"name": "'Elixir.AshAi.Mcp.Server':check_origin/2"}, {"name": "'Elixir.AshAi.Mcp.Server':origin_allowed?/3"}], "repo": "https://github.com/ash-project/ash_ai", "vendor": "ash-project", "versions": [{"lessThan": "28af68d73134df0b8fb3aa6ab03e8fd795b07c21", "status": "affected", "version": "c94f0b17fbe252f68755ba512678586164ba6139", "versionType": "git"}]}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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.\n\nIn 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.\n\nThis issue affects ash_ai: from 0.8.0 before 1.0.0."}], "id": "CVE-2026-81315", "lastModified": "2026-08-31T01:16:49.977", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-08-31T01:16:49.977", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-81315.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/ash-project/ash_ai/commit/28af68d73134df0b8fb3aa6ab03e8fd795b07c21"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/ash-project/ash_ai/security/advisories/GHSA-c92r-f3rr-q49h"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-81315"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-346"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

{}

{"created": "2026-08-31T02:30:18.313177+00:00", "updated": "2026-08-31T02:30:18.313182+00:00", "vendors": []}