{
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    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-82758",
        "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "state": "PUBLISHED",
        "assignerShortName": "EEF",
        "dateReserved": "2026-08-31T01:00:10.817Z",
        "datePublished": "2026-09-07T22:32:17.027Z",
        "dateUpdated": "2026-09-08T14:41:06.227Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://repo.hex.pm",
                    "cpes": [
                        "cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.AshAuthentication.Oauth2Server'"
                    ],
                    "packageName": "ash_authentication_oauth2_server",
                    "packageURL": "pkg:hex/ash_authentication_oauth2_server",
                    "product": "ash_authentication_oauth2_server",
                    "programFiles": [
                        "lib/ash_authentication/oauth2_server.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.AshAuthentication.Oauth2Server':__resolve_secret__!/3"
                        }
                    ],
                    "repo": "https://github.com/ash-project/ash_authentication_oauth2_server",
                    "vendor": "ash-project",
                    "versions": [
                        {
                            "lessThan": "0.3.1",
                            "status": "affected",
                            "version": "0.1.0",
                            "versionType": "semver"
                        }
                    ]
                },
                {
                    "collectionURL": "https://github.com",
                    "cpes": [
                        "cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.AshAuthentication.Oauth2Server'"
                    ],
                    "packageName": "ash-project/ash_authentication_oauth2_server",
                    "packageURL": "pkg:github/ash-project/ash_authentication_oauth2_server",
                    "product": "ash_authentication_oauth2_server",
                    "programFiles": [
                        "lib/ash_authentication/oauth2_server.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.AshAuthentication.Oauth2Server':__resolve_secret__!/3"
                        }
                    ],
                    "repo": "https://github.com/ash-project/ash_authentication_oauth2_server",
                    "vendor": "ash-project",
                    "versions": [
                        {
                            "lessThan": "30a87101871775d27d79f9ad6f29eafa4779e118",
                            "status": "affected",
                            "version": "855b578037c5ded18e8a6e60f42e56bde4905fae",
                            "versionType": "git"
                        }
                    ]
                }
            ],
            "configurations": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>Reachable only when the server configures an <code>initial_access_token</code> (so Dynamic Client Registration is meant to require one) and the configured secret provider returns an empty value (<code>nil</code>, <code>false</code>, or <code>\"\"</code>) or an <code>{:error, _}</code> for it, rather than a non-empty binary.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "Reachable only when the server configures an `initial_access_token` (so Dynamic Client Registration is meant to require one) and the configured secret provider returns an empty value (`nil`, `false`, or `\"\"`) or an `{:error, _}` for it, rather than a non-empty binary."
                        }
                    ],
                    "value": "Reachable only when the server configures an initial_access_token (so Dynamic Client Registration is meant to require one) and the configured secret provider returns an empty value (nil, false, or \"\") or an {:error, _} for it, rather than a non-empty binary."
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "cpeMatch": [
                                {
                                    "criteria": "cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "0.3.1",
                                    "versionStartIncluding": "0.1.0",
                                    "vulnerable": true
                                }
                            ],
                            "negate": false,
                            "operator": "OR"
                        }
                    ],
                    "operator": "AND"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "finder",
                    "value": "Peter Ullrich"
                },
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Peter Ullrich"
                },
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Zach Daniel / Ash Project"
                },
                {
                    "lang": "en",
                    "type": "coordinator",
                    "value": "Jonatan Männchen / EEF"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>Improper Authentication vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to register OAuth clients even when Dynamic Client Registration is gated by an initial access token.</p>\n<p><code>resolve_secret/3</code> in <code>AshAuthentication.Oauth2Server</code> (reached through <code>__resolve_secret__!</code>) treated any return other than <code>{:ok, _}</code> or <code>:error</code> from a configured <code>{module, function, args}</code> or 2-arity-function secret provider as a valid secret, wrapping <code>nil</code>, <code>false</code>, or <code>\"\"</code> as <code>{:ok, value}</code>. When the <code>initial_access_token</code> resolves to such an empty value, <code>POST /oauth/register</code> compares the presented bearer token against it and the comparison passes with no token supplied, so registration is open although it was configured closed. The same fail-open affected other resolved secrets such as <code>signing_secret</code>.</p>\n<p>This issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "Improper Authentication vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to register OAuth clients even when Dynamic Client Registration is gated by an initial access token.\n\n`resolve_secret/3` in `AshAuthentication.Oauth2Server` (reached through `__resolve_secret__!`) treated any return other than `{:ok, _}` or `:error` from a configured `{module, function, args}` or 2-arity-function secret provider as a valid secret, wrapping `nil`, `false`, or `\"\"` as `{:ok, value}`. When the `initial_access_token` resolves to such an empty value, `POST /oauth/register` compares the presented bearer token against it and the comparison passes with no token supplied, so registration is open although it was configured closed. The same fail-open affected other resolved secrets such as `signing_secret`.\n\nThis issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1."
                        }
                    ],
                    "value": "Improper Authentication vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to register OAuth clients even when Dynamic Client Registration is gated by an initial access token.\n\nresolve_secret/3 in AshAuthentication.Oauth2Server (reached through __resolve_secret__!) treated any return other than {:ok, _} or :error from a configured {module, function, args} or 2-arity-function secret provider as a valid secret, wrapping nil, false, or \"\" as {:ok, value}. When the initial_access_token resolves to such an empty value, POST /oauth/register compares the presented bearer token against it and the comparison passes with no token supplied, so registration is open although it was configured closed. The same fail-open affected other resolved secrets such as signing_secret.\n\nThis issue affects ash_authentication_oauth2_server: from 0.1.0 before 0.3.1."
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-115",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-115 Authentication Bypass"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "attackVector": "NETWORK",
                        "baseScore": 6.3,
                        "baseSeverity": "MEDIUM",
                        "privilegesRequired": "NONE",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "userInteraction": "NONE",
                        "valueDensity": "NOT_DEFINED",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0",
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                        "vulnerabilityResponseEffort": "NOT_DEFINED"
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                    "format": "CVSS",
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                            "value": "GENERAL"
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            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-287",
                            "description": "CWE-287 Improper Authentication",
                            "lang": "en",
                            "type": "CWE"
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                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
                "shortName": "EEF",
                "dateUpdated": "2026-09-07T22:32:17.027Z"
            },
            "references": [
                {
                    "tags": [
                        "vendor-advisory",
                        "related"
                    ],
                    "url": "https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-fxc6-vp68-87pw"
                },
                {
                    "tags": [
                        "related"
                    ],
                    "url": "https://cna.erlef.org/cves/CVE-2026-82758.html"
                },
                {
                    "tags": [
                        "related"
                    ],
                    "url": "https://osv.dev/vulnerability/EEF-CVE-2026-82758"
                },
                {
                    "tags": [
                        "patch"
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                    "url": "https://github.com/ash-project/ash_authentication_oauth2_server/commit/30a87101871775d27d79f9ad6f29eafa4779e118"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "title": "ash_authentication_oauth2_server treats an empty resolved secret as valid, opening the gated Dynamic Client Registration endpoint"
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-08T14:40:53.437993Z",
                                "id": "CVE-2026-82758",
                                "options": [
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                                        "Exploitation": "none"
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                                        "Technical Impact": "partial"
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                "title": "CISA ADP Vulnrichment",
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