# CVE-2026-26456: Null dereference in n/a

> A race condition in ccoap's session management causes a null pointer dereference, leading to 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:** 27 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** GHSA-59pv-qgfv-jx2f

## What is CVE-2026-26456?

CVE-2026-26456 is a high-severity vulnerability in n/a, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A null pointer dereference vulnerability exists in the server-side session management logic of ccoap 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5. The issue is caused by a race condition between the request dispatch thread and the session cleanup thread when accessing shared session list nodes without proper synchronization.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-26456?


## How do I fix CVE-2026-26456?

No fix has been published for CVE-2026-26456 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-26456 being exploited?

There is no known exploitation of CVE-2026-26456 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26456 and fix it if it is affected.

What it is: CVE-2026-26456 is a high-severity vulnerability in n/a, published on 27 Aug 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-2026-26456 in the wild and no public exploit code.

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-2026-26456/ (Markdown: https://insights.sbomify.com/CVE-2026-26456/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26456
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26456
- OSV: https://osv.dev/vulnerability/CVE-2026-26456

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26456/
Summaries are generated and may contain mistakes; the official description above is the record.