# CVE-2026-63446: Suricata app-layer: passed flows can retain transactions, causing resource exhaustion

> Attackers can cause resource exhaustion in Suricata by triggering a logic error that prevents transaction cleanup on passed flows.

- **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:** 18 Sep 2026
- **Updated:** 21 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-63446, GHSA-gjwr-75gq-877m, UBUNTU-CVE-2026-63446

## What is CVE-2026-63446?

CVE-2026-63446 is a high-severity denial of service vulnerability in Oisf Suricata, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.0 until 8.0.6, AppLayerParserSetTransactionInspectId() in src/app-layer-parser.c uses an inverted guard and marks only already-inspected transactions as inspected. On flows passed by a pass rule or pass-the-flow exception policy, detection is skipped, so completed transactions remain unmarked, are never freed, and are repeatedly rescanned. The per-flow list can grow without bound with quadratic cleanup cost, causing CPU and memory exhaustion. This issue is fixed in version 8.0.6.

Weakness: CWE-407 (Inefficient Algorithmic Complexity), CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-63446?

It affects 1 product.


Products: Oisf Suricata.

## How do I fix CVE-2026-63446?

Upgrade to a fixed version.

## Is CVE-2026-63446 being exploited?

There is no known exploitation of CVE-2026-63446 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-2026-63446 and fix it if it is affected.

What it is: CVE-2026-63446 is a high-severity denial of service vulnerability in Oisf Suricata, published on 18 Sep 2026. 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-2026-63446 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-2026-63446/ (Markdown: https://insights.sbomify.com/CVE-2026-63446/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63446
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63446
- OSV: https://osv.dev/vulnerability/CVE-2026-63446

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63446/
Summaries are generated and may contain mistakes; the official description above is the record.