CVE-2026-71250 Details
Description
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.
A vulnerability in Firefly III's webhook URL validator allows for blind server-side request forgery (SSRF). The validator, located in 'IsValidWebhookUrl.php', improperly handles private IPv4 ranges, specifically allowing addresses in the loopback range of 127.0.0.0/8. This flaw enables an authenticated user with webhooks enabled to configure a webhook that targets loopback services on the server. Additionally, the validation process resolves hostnames via 'gethostbyname()', but the actual webhook request, sent through 'StandardWebhookSender.php' using Guzzle, re-resolves the hostname at send time. This creates an opportunity for DNS rebinding attacks, where a validation check against a public IP could be exploited to send a request to a private or internal address. The response from the webhook is logged server-side for debugging, making this a blind SSRF vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Aug 5, 2026CISA-ADP
Assessed Aug 5, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/firefly-iii/firefly-iii | TuranSec | Vendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-918 | Server-Side Request Forgery (SSRF) | TuranSec |
Affected Products
| Product | Versions |
|---|---|
| Firefly III | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 10, 2026 | CVE Modified | TuranSec |
| Aug 5, 2026 | CVE Modified | CISA-ADP |
| Aug 5, 2026 | New CVE Received | TuranSec |