{"id":"CVE-2026-82757","title":"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?/…","summary":"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?/…","severity":"medium","cvss":6.3,"cvssVector":"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","cwe":["CWE-918"],"vendor":"ash-project","product":"ash_authentication_oauth2_server","affected":["ash_authentication_oauth2_server >= 0.3.0 < 0.3.1","ash-project/ash_authentication_oauth2_server >= e713a9ba816761140c226e2ca55b75c0b93f5984 < 268b591261a3473ab9b87272963e4dd2fd99d972"],"published":"2026-09-07","updated":"2026-09-08","sourceUpdated":"2026-09-08T15:18:50.823","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82757","references":[{"url":"https://cna.erlef.org/cves/CVE-2026-82757.html","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/ash-project/ash_authentication_oauth2_server/commit/268b591261a3473ab9b87272963e4dd2fd99d972","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-wprp-8gvj-p6cv","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82757","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-08T14:43:50.818031Z"},"cvssSource":"cna","epss":0.00665,"epssPercentile":0.49647,"ingestedAt":"2026-09-08T15:33:26.980Z","slug":"CVE-2026-82757","body":"## Overview\n\nServer-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":34.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}