CVE-2026-82757

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-82757
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82757.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-82757
Aliases
Published
2026-09-07T22:31:34Z
Modified
2026-09-10T03:30:24Z
Severity
  • 6.3 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
ash_authentication_oauth2_server CIMD fetcher classifies IPv4-in-IPv6 and site-local addresses as public, allowing SSRF
Details

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.

Database specific 
{
    "cna_assigner": "EEF",
    "cwe_ids": [
        "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82757.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "e713a9ba816761140c226e2ca55b75c0b93f5984"
                },
                {
                    "fixed": "268b591261a3473ab9b87272963e4dd2fd99d972"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/ash-project/ash_authentication_oauth2_server

Affected ranges

Type
GIT
Repo
https://github.com/ash-project/ash_authentication_oauth2_server
Events
Introduced
2681877faf2ef0df7d95852c2a72e9e972c64b7e
Fixed
15bde4311e31c925a428f34c02b283307619e2a2
Fixed
268b591261a3473ab9b87272963e4dd2fd99d972
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0.3.0"
        },
        {
            "fixed": "0.3.1"
        }
    ],
    "source": [
        "DESCRIPTION",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.3.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82757.json"