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

> Attackers can cause resource starvation and loss of visibility in Suricata by sending malformed HTTP/2 data on stream 0.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Jul 2025
- **Updated:** 23 Jul 2025
- **Also known as:** DEBIAN-CVE-2025-53538, GHSA-qrr7-crgj-cmh3, UBUNTU-CVE-2025-53538

## What is CVE-2025-53538?

CVE-2025-53538 is a high-severity denial of service vulnerability in Oisf Suricata, published on 22 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2025-53538?

It affects 1 product.


Products: Oisf Suricata.

## How do I fix CVE-2025-53538?

Upgrade to a fixed version.

## Is CVE-2025-53538 being exploited?

There is no known exploitation of CVE-2025-53538 in the wild and no public exploit code.

## Other vulnerabilities in Oisf Suricata

- [CVE-2023-35853](https://insights.sbomify.com/CVE-2023-35853/): Code injection in n/a (critical 9.8)
- [CVE-2021-37592](https://insights.sbomify.com/CVE-2021-37592/): Other in n/a (critical 9.8)
- [CVE-2018-10244](https://insights.sbomify.com/CVE-2018-10244/): Integer overflow in n/a (critical 9.8)
- [CVE-2026-94083](https://insights.sbomify.com/CVE-2026-94083/): Memory corruption in Suricata (critical 9.4)
- [CVE-2026-94084](https://insights.sbomify.com/CVE-2026-94084/): Use after free in Suricata (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-53538 and fix it if it is affected.

What it is: CVE-2025-53538 is a high-severity denial of service vulnerability in Oisf Suricata, published on 22 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-53538 in the wild and no public exploit code.

Affected product: Oisf Suricata. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-53538/ (Markdown: https://insights.sbomify.com/CVE-2025-53538/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-53538
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-53538
- OSV: https://osv.dev/vulnerability/CVE-2025-53538

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-53538/
Summaries are generated and may contain mistakes; the official description above is the record.