CVE-2026-1555: WebStack <= 1.2024 - Unauthenticated Arbitrary File Upload

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-15 · updated 2026-10-26
Weakness: CWE-434

Description

The WebStack theme for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the io_img_upload() function in all versions up to, and including, 1.2024. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible.

Affected products

Owen WebStack: through 1.2024

References

https://github.com/owen0o0/WebStack/blob/master/inc/ajax.php#L5
https://github.com/owen0o0/WebStack/tree/master
https://www.wordfence.com/threat-intel/vulnerabilities/id/b97805de-1b47-4c9f-baae-2e37c1b78570?source=cve

Get alerted when CVE-2026-1555 or the next vulnerability affects your stack