CVE-2026-71250
Firefly III - Webhook URL Validation Explicitly Allows Loopback and Is Bypassable via DNS Rebinding
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
0th
Firefly III's webhook URL validator (IsValidWebhookUrl.php) filters most private/reserved IPv4 ranges but contains an explicit early-return that allows any resolved address in 127.0.0.0/8, permitting an authenticated user (with webhooks enabled, which is off by default) to configure a webhook targeting loopback services on the server.
| CWE | CWE-918 |
| Vendor | firefly-iii |
| Product | firefly-iii |
| Published | Aug 5, 2026 |
| Last Updated | Aug 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
firefly-iii / firefly-iii
0
Credits
Bobur Abdugafforov