CVE-2026-4127
Speedup Optimization <= 1.5.9 - Missing Authorization to Authenticated (Subscriber+) Plugin Settings Update via 'speedup01_enabled' AJAX Action
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The speedup01_ajax_enabled() function, which handles the wp_ajax_speedup01_enabled AJAX action, does not perform any capability check via current_user_can() and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., speedup01_ajax_install_iox and speedup01_ajax_delete_cache_file) which properly check for install_plugins and manage_options capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.3
Speedup Optimization <= 1.5.9 - Missing Authorization to Authenticated (Subscriber+) Plugin Settings Update via 'speedup01_enabled' AJAX Action
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The speedup01_ajax_enabled() function, which handles the wp_ajax_speedup01_enabled AJAX action, does not perform any capability check via current_user_can() and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., speedup01_ajax_install_iox and speedup01_ajax_delete_cache_file) which properly check for install_plugins and manage_options capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
- Record
CVE-2026-4127- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2026-13995
4.3
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The speedup01_ajax_enabled() function, which handles the wp_ajax_speedup01_enabled AJAX action, does not perform any capability check via current_user_can() and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., speedup01_ajax_install_iox and speedup01_ajax_delete_cache_file) which properly check for install_plugins and manage_options capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
- Record
EUVD-2026-13995- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r2gp-fxxq-xp2g
5.3
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all...
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The speedup01_ajax_enabled() function, which handles the wp_ajax_speedup01_enabled AJAX action, does not perform any capability check via current_user_can() and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., speedup01_ajax_install_iox and speedup01_ajax_delete_cache_file) which properly check for install_plugins and manage_options capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
- Record
GHSA-r2gp-fxxq-xp2g- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
NVD
4.3
The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The speedup01_ajax_enabled() function, which handles the wp_ajax_speedup01_enabled AJAX action, does not perform any capability check via current_user_can() and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., speedup01_ajax_install_iox and speedup01_ajax_delete_cache_file) which properly check for install_plugins and manage_options capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
- Record
CVE-2026-4127- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-4127 is a medium vulnerability (CVSS 4.3) in Charlycharm Speedup Optimization, published March 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/3f37c650-af0d-4474-9c1b-7f8d361b4d81?source=cve
plugins.trac.wordpress.org/browser/speedup-optimization/trunk/speedup-optimization.php
plugins.trac.wordpress.org/browser/speedup-optimization/tags/1.5.9/speedup-optimization.php
nvd.nist.gov/vuln/detail/CVE-2026-4127
github.com/advisories/GHSA-r2gp-fxxq-xp2g