# CVE-2025-56233: Denial of service in n/a

> Attackers can disrupt TCP connections by sending random RST or SYN packets within the acceptable sequence number range, causing denial of service.

- **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:** No
- **Published:** 29 Sep 2025
- **Updated:** 28 Oct 2025
- **Also known as:** GHSA-325f-j5c3-chxm

## What is CVE-2025-56233?

CVE-2025-56233 is a high-severity denial of service vulnerability in n/a, published on 29 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Openindiana, kernel SunOS 5.11 has a denial of service vulnerability. For the processing of TCP packets with RST or SYN flag set, Openindiana has a wide acceptable range of sequence numbers. It does not require the sequence number to exactly match the next expected sequence value, just to be within the current receive window, which violates RFC5961. This flaw allows attackers to send multiple random TCP RST/SYN packets to hit the acceptable range of sequence numbers, thereby interrupting normal connections and causing a denial of service attack.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2025-56233?


## How do I fix CVE-2025-56233?

No fix has been published for CVE-2025-56233 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-56233 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-56233 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-56233 and fix it if it is affected.

What it is: CVE-2025-56233 is a high-severity denial of service vulnerability in n/a, published on 29 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-56233 exists.

Affected product: n/a. 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-2025-56233/ (Markdown: https://insights.sbomify.com/CVE-2025-56233/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-56233
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-56233
- OSV: https://osv.dev/vulnerability/CVE-2025-56233

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-56233/
Summaries are generated and may contain mistakes; the official description above is the record.