Instant CSS <= 1.1.4 - Missing Authorization via AJAX Actions
The Instant CSS plugin for WordPress is vulnerable to unauthorized access and modification of data due to missing capability checks on several functions called via AJAX actions in the ~/classes/class.instantcss_ajax.php file in versions up to, and including, 1.1.4. This makes it possible for authenticated attackers, with subscriber-level access and above, to perform a wide variety of actions such as retrieving css, theme, and minify data, along with updating the options for those. The unprotected AJAX actions present can be used to exploit a site via Cross-Site Scripting as well.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| WordPress plugin | Instant CSS | <= 1.1.4 | 1.1.5 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N- Weakness (CWE)
CWE-862- Platform
- WordPress
- Package
Instant CSS- Disclosed
- 24.07.2023
- Updated
- 11.10.2026 10:23
Sources and licenses
Wordfence Intelligence - b82a9ae8-ff82-40bf-a5d4-5175daab9146 - Wordfence Intelligence
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Copyright 2012-2026 Defiant Inc.
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Vulnerability history: Instant CSS
All published vulnerabilities of this package (WordPress plugin), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 07.2023 09.2023
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
Disclosures per year
- 2023: 2
- 2024: 0
- 2025: 0
- 2026: 0
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Instant CSS <= 1.1.4 - Missing Authorization via AJAX Actions this entry
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