Description
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. 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. This issue affects ash_authentication_oauth2_server: from 0.3.0 before 0.3.1.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
ash-project ash_authentication_oauth2_server
Default version status: unaffected
0.3.0 to < 0.3.1affected
pkg:hex/ash_authentication_oauth2_serverash-project ash_authentication_oauth2_server
Default version status: unaffected
e713a9ba816761140c226e2ca55b75c0b93f5984 to < 268b591261a3473ab9b87272963e4dd2fd99d972affected
pkg:github/ash-project/ash_authentication_oauth2_serverReferences
- https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-wprp-8gvj-p6cv ↗
- https://cna.erlef.org/cves/CVE-2026-82757.html ↗
- https://osv.dev/vulnerability/EEF-CVE-2026-82757 ↗
- https://github.com/ash-project/ash_authentication_oauth2_server/commit/268b591261a3473ab9b87272963e4dd2fd99d972 ↗