CVE-2026-6255 is a stored cross-site scripting vulnerability in the Simple Owl Shortcodes WordPress plugin, affecting all versions up to and including 2.1.1. The issue stems from improper neutralization of input in the 'num' attribute of the 'owls_wrapper' shortcode, allowing authenticated users with contributor-level permissions or higher to inject arbitrary web scripts. These scripts execute in the context of users visiting the injected pages, potentially leading to session hijacking or other script-based attacks. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting network attack vector, low attack complexity, and privileges required at the contributor level without user interaction.

An attacker with contributor-level or higher access can inject persistent malicious scripts into pages via the vulnerable shortcode attribute. This can lead to unauthorized script execution in the browsers of users who visit the compromised pages, potentially resulting in data theft or session compromise. The vulnerability does not impact availability and requires authenticated access, limiting its scope somewhat. No known active exploitation has been reported.

No official patch or remediation is currently available for this vulnerability. Users should monitor the vendor's advisory channels for updates. Until a fix is released, restrict contributor-level access to trusted users only and consider disabling or removing the Simple Owl Shortcodes plugin if feasible to reduce risk.