CVE-2025-53538: 
Suricata vulnerability analysis and mitigation

CVE-2025-53538 affects Suricata, a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation). The vulnerability was discovered in versions 7.0.10 and below, and 8.0.0-beta1 through 8.0.0-rc1, where mishandling of data on HTTP2 stream 0 can lead to uncontrolled memory usage. The issue was disclosed on July 22, 2025 (NVD).

The vulnerability stems from improper handling of data on HTTP2 stream 0, which violates RFC 9113 section 6.1 specifications. The issue is related to uncontrolled resource consumption (CWE-770 and CWE-400). The vulnerability has received a CVSS v3.1 base score of 7.5 (High) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating it can be exploited remotely with no privileges required (GitHub Advisory).

The primary impact of this vulnerability is the potential for uncontrolled memory usage, which can lead to loss of visibility in the network monitoring system. This affects the availability of the system without compromising confidentiality or integrity (GitHub Advisory).

Two primary mitigation options are available: 1) Upgrade to patched versions 7.0.11 or 8.0.0, or 2) Implement a temporary workaround by either disabling the HTTP/2 parser or using a signature like 'drop http2 any any -> any any (frame:http2.hdr; byte_test:1,=,0,3; byte_test:4,=,0,5; sid: 1;)' where the first byte test checks the HTTP2 frame type DATA and the second tests the stream id 0 (GitHub Advisory).