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.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Firefly-iii |
|
No data.
No data.
References
| Link | Providers |
|---|---|
| https://github.com/firefly-iii/firefly-iii |
|
History
Mon, 10 Aug 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. Additionally, the validator resolves the target hostname once via gethostbyname() at validation time, but the actual outbound request (StandardWebhookSender.php, via Guzzle) re-resolves the hostname independently at send time, allowing a DNS-rebinding attacker to pass validation against a public IP and have the real request delivered to a private or internal address. The webhook response body is only written to a server-side debug log, not returned to the triggering user, so this is a blind SSRF primitive rather than one with direct response read-back. | 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. |
Mon, 10 Aug 2026 11:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | Firefly III: Webhook URL Validation Explicitly Allows Loopback and Is Bypassable via DNS Rebinding | Firefly III - Webhook URL Validation Explicitly Allows Loopback and Is Bypassable via DNS Rebinding |
Wed, 05 Aug 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 05 Aug 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Firefly-iii
Firefly-iii firefly Iii |
|
| Vendors & Products |
Firefly-iii
Firefly-iii firefly Iii |
Wed, 05 Aug 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. Additionally, the validator resolves the target hostname once via gethostbyname() at validation time, but the actual outbound request (StandardWebhookSender.php, via Guzzle) re-resolves the hostname independently at send time, allowing a DNS-rebinding attacker to pass validation against a public IP and have the real request delivered to a private or internal address. The webhook response body is only written to a server-side debug log, not returned to the triggering user, so this is a blind SSRF primitive rather than one with direct response read-back. | |
| Title | Firefly III: Webhook URL Validation Explicitly Allows Loopback and Is Bypassable via DNS Rebinding | |
| Weaknesses | CWE-918 | |
| References |
| |
| Metrics |
cvssV3_1
|
MITRE
Status: PUBLISHED
Assigner: TuranSec
Published: 2026-08-05T10:57:08.628Z
Updated: 2026-08-10T11:46:07.818Z
Reserved: 2026-08-05T10:53:53.177Z
Link: CVE-2026-71250
Vulnrichment
Updated: 2026-08-05T12:41:23.092Z
NVD
Status : Received
Published: 2026-08-05T11:16:28.110
Modified: 2026-08-10T12:17:27.630
Link: CVE-2026-71250
Redhat
No data.