CVE-2026-82757
Severity not reportedServer-Side Request Forgery (SSRF) vulnerability in ash-project ash_authentication_oauth2_server allows an attacker who controls a client metadata URL and its…
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
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://cna.erlef.org/cves/CVE-2026-82757.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/ash-project/ash_authentication_oauth2_server/commit/268b591261a3473ab9b... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-w... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://osv.dev/vulnerability/EEF-CVE-2026-82757 6b3ad84c-e1a6-4bf7-a703-f496b71e49db