CVE-2024-13926: 
WordPress vulnerability analysis and mitigation

The WP-Syntax WordPress plugin through version 1.2 contains a vulnerability that allows attackers to create posts with numerous tags, leading to a catastrophic backtracking issue in regular expression processing. This vulnerability was discovered and publicly disclosed on March 28, 2025, and has been assigned CVE-2024-13926 (WPScan, NVD).

The vulnerability stems from improper input handling in the WP-Syntax plugin. When processing posts containing a large number of tags, the plugin's regular expression processing mechanism experiences catastrophic backtracking, which can be exploited to cause high CPU utilization. Testing has shown that each malicious request can consume 100% of a CPU core for several seconds on an Intel i7 2.80GHz CPU. The vulnerability has been assigned a CVSS v3.1 base score of 7.5 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (WPScan).

When exploited, this vulnerability can lead to a Denial of Service (DoS) condition by consuming excessive CPU resources. The impact is particularly severe as concurrent requests to a page containing the malicious payload can significantly degrade server performance (WPScan).

The vulnerability can be exploited by any user with author-level privileges or higher. A proof of concept exists that demonstrates how an attacker can generate a payload (e.g., using PHP's str_repeat function with 20,000 iterations) and trigger multiple concurrent requests to cause the DoS condition. The exploit code is publicly available (WPScan).

Currently, there is no known fix available for this vulnerability in the WP-Syntax plugin (WPScan).