SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-33731

In versions prior to 29.0, the Authorize.Net webhook handler at plugin/AuthorizeNet/webhook.php contains a signature verification bypass that allows an attacker to forge webhook requests with arbitrary payment amounts and target user IDs.

MEDIUM 6.5EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

Description

WWBN AVideo is an open source video platform. In versions prior to 29.0, the Authorize.Net webhook handler at plugin/AuthorizeNet/webhook.php contains a signature verification bypass that allows an attacker to forge webhook requests with arbitrary payment amounts and target user IDs. By supplying a valid transaction ID from a small legitimate purchase, the attacker bypasses signature validation and credits arbitrary wallet balances to any user account via attacker-controlled payload fields. Three flaws combine into an exploit chain: signature bypass via OR logic (webhook.php:33), payload values override API-fetched values (AuthorizeNet.php:169-171, webhook.php:44-48) and a missing approval check (webhook.php:61-75). By forging payment metadata, an attacker can credit arbitrary amounts to any user's wallet without a corresponding payment and include a  plans_id  to activate premium subscriptions (webhook.php:86-134), enabling free access to all paid and premium content and causing direct revenue loss to the platform owner. This issue has been fixed in version 29.0.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS
0.21% probability · 11th percentile
CISA KEV
Not listed
Weakness
CWE-345
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.