# CVE-2026-116540: netty-tcnative 2.0.66.Final before 2.0.84.Final Use-After-Free in Session Ticket Callback


- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 26 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-116540, GHSA-fgcj-53j7-r6vq, GHSA-mmc8-vg2v-fvvw, UBUNTU-CVE-2026-116540

## What is CVE-2026-116540?

CVE-2026-116540 is a high-severity vulnerability in netty-tcnative, published on 26 Oct 2026. 

### Official description

netty-tcnative 2.0.66.Final before 2.0.84.Final built against OpenSSL 3.x contains a use-after-free vulnerability in ssl_tlsext_ticket_key_cb during session ticket key rotation. Remote clients performing TLS handshakes while setSessionTicketKeys0 frees the shared key array cause OpenSSL to read freed HMAC keys, crashing or corrupting ticket processing.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-116540?


## How do I fix CVE-2026-116540?

No fix has been published for CVE-2026-116540 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-116540 being exploited?

There is no known exploitation of CVE-2026-116540 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116540 and fix it if it is affected.

What it is: CVE-2026-116540 is a high-severity vulnerability in netty-tcnative, published on 26 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-116540 in the wild and no public exploit code.

Affected product: netty-tcnative. 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-2026-116540/ (Markdown: https://insights.sbomify.com/CVE-2026-116540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116540
- OSV: https://osv.dev/vulnerability/CVE-2026-116540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116540/
Summaries are generated and may contain mistakes; the official description above is the record.