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CVE-2026-82757

ash_authentication_oauth2_server CIMD fetcher classifies IPv4-in-IPv6 and site-local addresses as public, allowing SSRF PUBLISHED

Description (CNA)

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 (CNA)

Vendor / productVersions
ash-project / ash_authentication_oauth2_serveraffected 0.3.0 before 0.3.1
ash-project / ash_authentication_oauth2_serveraffected e713a9ba816761140c226e2ca55b75c0b93f5984 before 268b591261a3473ab9b87272963e4dd2fd99d972

CWE

CWE-918

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.