Resource exhaustion in Oisf Suricata
CVE-2025-53538
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. In versions 7.0.10 and below and 8.0.0-beta1 through 8.0.0-rc1, mishandling of data on HTTP2 stream 0 can lead to uncontrolled memory usage, leading to loss of visibility. Workarounds include disabling the HTTP/2 parser, and 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 tests the HTTP2 frame type DATA and the second tests the stream id 0. This is fixed in versions 7.0.11 and 8.0.0.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.004 (35.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Oisf Suricata — versions >= 8.0.0-beta1, < 8.0.0, 8.0.0, < 7.0.11
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-53538?
- CVE-2025-53538 is a high-severity vulnerability in Oisf Suricata, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-07-22.
- How severe is CVE-2025-53538?
- High severity. CVSS v3 base score is 7.5 out of 10.