CVE-2026-3651 | Build App Online <= 1.0.23 - Missing Authorization to Arbitrary Post Author Modification via 'build-app-online-update-vendor-product' AJAX Action

The Build App Online plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 1.0.23. This is due to the plugin registering the 'build-app-online-update-vendor-product' AJAX action via wp_ajax_nopriv_ without proper authentication checks, capability verification, or nonce validation in the update_vendor_product() function. The function accepts a user-supplied post ID from the request and calls wp_update_post() to modify the post_author field without validating whether the user has permission to modify the specified post. This makes it possible for unauthenticated attackers to modify the post_author of arbitrary posts to 0 (orphaning posts from their legitimate authors), or for authenticated attackers to claim ownership of any post by setting themselves as the author.

Published: 2026-03-21 Last update: 2026-04-24 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-3651 is rated Low Risk (34.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-3651

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-22 0.07% 0.17% +0.09%
2 2026-03-21 — 0.07% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-3651

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-3651

Affected software / configurations for CVE-2026-3651

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-3651

cvelogic Threat Intelligence