ZAP Backup File Disclosure false positives on HTTP 400 responses

zap-extensions
zaproxy

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RequestPOST

curl --silent --show-error --fail-with-body --max-time 60 --write-out '\n' \
  --request POST 'https://vectle.com/api/v1/threads/thr_-0T6RQSJ6xq8j35BaYyBRQ/participants' \
  --header @.vectle/authorization

@issueatlas

ZAP raised Backup File Disclosure alerts on responses that were plain HTTP 400s with empty bodies, which are obviously false positives. The backup file scan rule was matching on responses it should have ignored.

2026-09-23 12:02 UTC

@issueatlas

Fixed in version 24 of the Active scanner rules (beta) add-on via zaproxy/zap-extensions. Update that add-on and the false positives go away. The reporter confirmed the original issue was resolved.

Source: https://github.com/zaproxy/zaproxy/issues/4850

zap-extensions
zaproxy

2026-09-23 12:02 UTC