{"id":"CVE-2026-82731","state":"PUBLISHED","title":"Unescaped path parameters in AshTypescript generated TypeScript client allow request redirection","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.\n\nThe 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.\n\nThe query-string path is unaffected, since URLSearchParams.set encodes its own values.\n\nThis issue affects ash_typescript: from 0.15.0 before 0.18.0.","publishedAt":"2026-09-01T02:09:38.801Z","updatedAt":"2026-09-01T15:13:54.605Z","severity":{"score":2.3,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N","source":"EEF"},"assigner":"EEF","products":["ash-project ash_typescript"],"affected":[{"vendor":"ash-project","product":"ash_typescript","packageName":"ash_typescript","packageURL":"pkg:hex/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"0.15.0","status":"affected","lessThan":"0.18.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer'"],"programFiles":["lib/ash_typescript/typed_controller/codegen/route_renderer.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer':build_url_template_to_variable/4"}],"repo":"https://github.com/ash-project/ash_typescript"},{"vendor":"ash-project","product":"ash_typescript","packageName":"ash-project/ash_typescript","packageURL":"pkg:github/ash-project/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"6669e22ece34b4534e706a46d1842f01b68ee23a","status":"affected","lessThan":"5165f752f5f92b755d946f2d1ce750ff69083ffc","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer'"],"programFiles":["lib/ash_typescript/typed_controller/codegen/route_renderer.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer':build_url_template_to_variable/4"}],"repo":"https://github.com/ash-project/ash_typescript"}],"references":["https://github.com/ash-project/ash_typescript/security/advisories/GHSA-6g23-p936-fm2f","https://cna.erlef.org/cves/CVE-2026-82731.html","https://osv.dev/vulnerability/EEF-CVE-2026-82731","https://github.com/ash-project/ash_typescript/commit/5165f752f5f92b755d946f2d1ce750ff69083ffc"],"weaknesses":["CWE-601"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/82xxx/CVE-2026-82731.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-82731","state":"PUBLISHED","datePublished":"2026-09-01T02:09:38.801Z","dateUpdated":"2026-09-01T15:13:54.605Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-08-31T00:59:08.960Z"},"containers":{"cna":{"title":"Unescaped path parameters in AshTypescript generated TypeScript client allow request redirection","descriptions":[{"lang":"en","value":"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.\n\nThe 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.\n\nThe query-string path is unaffected, since URLSearchParams.set encodes its own values.\n\nThis issue affects ash_typescript: from 0.15.0 before 0.18.0."}],"affected":[{"vendor":"ash-project","product":"ash_typescript","packageName":"ash_typescript","packageURL":"pkg:hex/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"0.15.0","status":"affected","lessThan":"0.18.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer'"],"programFiles":["lib/ash_typescript/typed_controller/codegen/route_renderer.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer':build_url_template_to_variable/4"}],"repo":"https://github.com/ash-project/ash_typescript"},{"vendor":"ash-project","product":"ash_typescript","packageName":"ash-project/ash_typescript","packageURL":"pkg:github/ash-project/ash_typescript","defaultStatus":"unaffected","versions":[{"version":"6669e22ece34b4534e706a46d1842f01b68ee23a","status":"affected","lessThan":"5165f752f5f92b755d946f2d1ce750ff69083ffc","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer'"],"programFiles":["lib/ash_typescript/typed_controller/codegen/route_renderer.ex"],"programRoutines":[{"name":"'Elixir.AshTypescript.TypedController.Codegen.RouteRenderer':build_url_template_to_variable/4"}],"repo":"https://github.com/ash-project/ash_typescript"}],"references":[{"url":"https://github.com/ash-project/ash_typescript/security/advisories/GHSA-6g23-p936-fm2f","tags":["related","vendor-advisory"]},{"url":"https://cna.erlef.org/cves/CVE-2026-82731.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82731","tags":["related"]},{"url":"https://github.com/ash-project/ash_typescript/commit/5165f752f5f92b755d946f2d1ce750ff69083ffc","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":2.3,"baseSeverity":"LOW","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-601","description":"CWE-601 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parameter."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*","versionEndExcluding":"0.18.0","versionStartIncluding":"0.15.0","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":"Torkild Gundersen Kjevik / Ash Project"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-72","descriptions":[{"lang":"en","value":"CAPEC-72 URL Encoding"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP 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