{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher'"],"packageName":"ash_authentication_oauth2_server","packageURL":"pkg:hex/ash_authentication_oauth2_server","product":"ash_authentication_oauth2_server","programFiles":["lib/ash_authentication/oauth2_server/cimd/req_fetcher.ex"],"programRoutines":[{"name":"'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher':public_ip?/1"},{"name":"'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher':fetch/2"}],"repo":"https://github.com/ash-project/ash_authentication_oauth2_server","vendor":"ash-project","versions":[{"lessThan":"0.3.1","status":"affected","version":"0.3.0","versionType":"semver"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher'"],"packageName":"ash-project/ash_authentication_oauth2_server","packageURL":"pkg:github/ash-project/ash_authentication_oauth2_server","product":"ash_authentication_oauth2_server","programFiles":["lib/ash_authentication/oauth2_server/cimd/req_fetcher.ex"],"programRoutines":[{"name":"'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher':public_ip?/1"},{"name":"'Elixir.AshAuthentication.Oauth2Server.CIMD.ReqFetcher':fetch/2"}],"repo":"https://github.com/ash-project/ash_authentication_oauth2_server","vendor":"ash-project","versions":[{"lessThan":"268b591261a3473ab9b87272963e4dd2fd99d972","status":"affected","version":"e713a9ba816761140c226e2ca55b75c0b93f5984","versionType":"git"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Reachable only when Client ID Metadata Documents are enabled (<code>cimd_enabled?: true</code>), so the authorize endpoint fetches attacker-suppliable metadata URLs, and an internal or loopback target resolves to one of the affected IPv6 address forms.</p>"},{"base64":false,"type":"text/markdown","value":"Reachable only when Client ID Metadata Documents are enabled (`cimd_enabled?: true`), so the authorize endpoint fetches attacker-suppliable metadata URLs, and an internal or loopback target resolves to one of the affected IPv6 address forms."}],"value":"Reachable only when Client ID Metadata Documents are enabled (cimd_enabled?: true), so the authorize endpoint fetches attacker-suppliable metadata URLs, and an internal or loopback target resolves to one of the affected IPv6 address forms."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*","versionEndExcluding":"0.3.1","versionStartIncluding":"0.3.0","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 Männchen / EEF"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Server-Side Request Forgery (SSRF) vulnerability in ash-project ash_authentication_oauth2_server allows an attacker who controls a client metadata URL and its DNS to make the server connect to internal or loopback addresses.</p>\n<p><code>public_ip?/1</code> in <code>AshAuthentication.Oauth2Server.CIMD.ReqFetcher</code> enforces the outbound policy for CIMD metadata fetches. It classified several address forms as publicly routable that are not: IPv4-compatible <code>::/96</code> (for example <code>::127.0.0.1</code>), SIIT IPv4-translated <code>::ffff:0:0:0/96</code>, and deprecated site-local <code>fec0::/10</code>. A returned AAAA record in one of these ranges passed the policy, so a fetch pinned to that address reached space the policy was meant to block.</p>\n<p>This issue affects ash_authentication_oauth2_server: from 0.3.0 before 0.3.1.</p>"},{"base64":false,"type":"text/markdown","value":"Server-Side Request Forgery (SSRF) vulnerability in ash-project ash_authentication_oauth2_server allows an attacker who controls a client metadata URL and its DNS to make the server connect to internal or loopback addresses.\n\n`public_ip?/1` in `AshAuthentication.Oauth2Server.CIMD.ReqFetcher` enforces the outbound policy for CIMD metadata fetches. It classified several address forms as publicly routable that are not: IPv4-compatible `::/96` (for example `::127.0.0.1`), SIIT IPv4-translated `::ffff:0:0:0/96`, and deprecated site-local `fec0::/10`. A returned AAAA record in one of these ranges passed the policy, so a fetch pinned to that address reached space the policy was meant to block.\n\nThis issue affects ash_authentication_oauth2_server: from 0.3.0 before 0.3.1."}],"value":"Server-Side Request Forgery (SSRF) vulnerability in ash-project ash_authentication_oauth2_server allows an attacker who controls a client metadata URL and its DNS to make the server connect to internal or loopback addresses.\n\npublic_ip?/1 in AshAuthentication.Oauth2Server.CIMD.ReqFetcher enforces the outbound policy for CIMD metadata fetches. It classified several address forms as publicly routable that are not: IPv4-compatible ::/96 (for example ::127.0.0.1), SIIT IPv4-translated ::ffff:0:0:0/96, and deprecated site-local fec0::/10. A returned AAAA record in one of these ranges passed the policy, so a fetch pinned to that address reached space the policy was meant to block.\n\nThis issue affects ash_authentication_oauth2_server: from 0.3.0 before 0.3.1."}],"impacts":[{"capecId":"CAPEC-664","descriptions":[{"lang":"en","value":"CAPEC-664 Server Side Request Forgery"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","description":"CWE-918 Server-Side Request Forgery (SSRF)","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-07T22:31:34.656Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory","related"],"url":"https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-wprp-8gvj-p6cv"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-82757.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82757"},{"tags":["patch"],"url":"https://github.com/ash-project/ash_authentication_oauth2_server/commit/268b591261a3473ab9b87272963e4dd2fd99d972"}],"source":{"discovery":"EXTERNAL"},"title":"ash_authentication_oauth2_server CIMD fetcher classifies IPv4-in-IPv6 and site-local addresses as public, allowing SSRF"}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-82757","datePublished":"2026-09-07T22:31:34.656Z","dateReserved":"2026-08-31T01:00:10.817Z","dateUpdated":"2026-09-07T22:31:34.656Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}