CVE-2026-71250

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CVSS 3.1

4.3 medium

EPSS

<1%p12

Published

Aug 5, 2026 (Aug 5, 2026)

Modified

Aug 26, 2026

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.

Weakness: CWE-918
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

NVD CVE.org GitHub PoCs EPSS (0.2%)

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