CVE-2025-53537: 
Suricata vulnerability analysis and mitigation

LibHTP, a security-aware parser for the HTTP protocol, has been found to contain a vulnerability (CVE-2025-53537) affecting versions 0.5.50 and below. The vulnerability was discovered and disclosed on July 23, 2025, and involves a traffic-induced memory leak that can affect system resources (GitHub Advisory).

The vulnerability has been assigned a CVSS v3.1 base score of 7.5 (High), with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. The technical assessment indicates that this is a CWE-401 (Missing Release of Memory after Effective Lifetime) issue, where the application fails to properly release allocated memory after its effective lifetime (GitHub Advisory).

The primary impact of this vulnerability is on system availability. When exploited, the memory leak can progressively consume system resources, eventually leading to resource starvation and potential loss of visibility in the affected system (GitHub Advisory).

A patch has been released in version 0.5.51 which addresses the memory leak. For systems unable to immediately update, a workaround is available by setting 'suricata.yaml app-layer.protocols.http.libhtp.default-config.lzma-enabled' to false (GitHub Advisory).