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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.005 (38.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-53538: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.000

Affected products

  • Oisf Suricata — versions >= 8.0.0-beta1, < 8.0.0, 8.0.0, < 7.0.11

Weakness classification (CWE)

References

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.