Donation status manipulation via unsigned Square webhooks
Published Aug 21, 2026 · Updated Aug 21, 2026
Authentication bypass in the Charitable WordPress plugin before 1.8.12 allows remote attackers to mark unpaid donations as paid. The public square_core listener accepts a payment.updated JSON event when merchant_id is merely present, without validating a Square signature. The Square gateway must be active without a stored signing secret, and a pending donation order ID must exist; the forged event completes that donation without payment.
Summary
What happened
Authentication bypass in the Charitable WordPress plugin before 1.8.12 allows remote attackers to mark unpaid donations as paid. The public square_core listener accepts a payment.updated JSON event when merchant_id is merely present, without validating a Square signature. The Square gateway must be active without a stored signing secret, and a pending donation order ID must exist; the forged event completes that donation without payment.
The record
- CVE
- CVE-2026-16650
- Published
- Aug 21, 2026
- Updated
- Aug 21, 2026
- Vendor
- Awesome Motive
- Product
- Charitable
- Classifications
- CWE-345, T1565.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 21, 2026CVE publishedPublication date reported by the CVE source.
- Aug 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.8.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Unsigned Square payment.updated webhook requestfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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