CVE-2026-7638 | App Builder <= 5.5.10 - Insecure Direct Object Reference to Authenticated (Subscriber+) Arbitrary User Avatar Modification via 'user_id' Parameter

The App Builder – Create Native Android & iOS Apps On The Flight plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to and including 5.6.0. This is due to missing authorization validation in the `upload_avatar()` function, which accepts an attacker-controlled `user_id` parameter from the POST request body and uses it to update user meta without verifying that the authenticated requester owns or has permission to modify the target account. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the profile avatar of any arbitrary user on the site, including administrators, by supplying a target `user_id` in the request body to the `/wp-json/app-builder/v1/upload-avatar` endpoint.

Published: 2026-05-02 Last update: 2026-05-05 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-7638 is rated Low Risk (27.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: 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-2026-7638

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 2026-05-08 0.04% 0.06% +0.01%
2 2026-05-02 0.04%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-7638

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-2026-7638

GitHub Security Advisory for CVE-2026-7638

GHSA-5rjg-2j76-x2r5 · Severity: medium — The App Builder – Create Native Android & iOS Apps On The Flight plugin for WordPress is...

Affected software / configurations for CVE-2026-7638

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-7638

URL Tags
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.5.10/includes/Di/Service/Auth/UploadAvatar.php#L161
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.5.10/includes/Di/Service/Auth/UploadAvatar.php#L80
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.5.10/includes/Traits/Permission.php#L33
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.6.0/includes/Di/Service/Auth/UploadAvatar.php#L161
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.6.0/includes/Di/Service/Auth/UploadAvatar.php#L80
https://plugins.trac.wordpress.org/browser/app-builder/tags/5.6.0/includes/Traits/Permission.php#L33
https://plugins.trac.wordpress.org/browser/app-builder/trunk/includes/Di/Service/Auth/UploadAvatar.php#L161
https://plugins.trac.wordpress.org/browser/app-builder/trunk/includes/Di/Service/Auth/UploadAvatar.php#L80
https://plugins.trac.wordpress.org/browser/app-builder/trunk/includes/Traits/Permission.php#L33
https://www.wordfence.com/threat-intel/vulnerabilities/id/2d532ffc-c6f1-41e3-9a59-0706802ab8e2?source=cve
cvelogic Threat Intelligence