# CVE-2026-12935: Unauthenticated Remote Code Execution in TP-Link TL-WR940N RTSP Conntrack Feature

> An unauthenticated attacker can trigger a stack-based buffer overflow in the RTSP conntrack module, leading to remote code execution or denial of service on the router.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 29 Jul 2026
- **Updated:** 30 Jul 2026
- **Also known as:** GHSA-4j6v-4j5m-vgpq

## What is CVE-2026-12935?

CVE-2026-12935 is a high-severity memory corruption vulnerability in TP-Link Systems Inc. TL-WR940N v6, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The
TL-WR940N v6 router contains a vulnerability in its RTSP connection tracking
module that can lead to a stack-based buffer overflow. The issue occurs when a
LAN client initiates a connection to a malicious RTSP server controlled by an
attacker. A specially crafted RTSP message may trigger improper memory handling
within the kernel module

Successful
exploitation of this vulnerability may result in a denial-of-service (DoS)
condition or allow remote code execution (RCE), potentially leading to full
compromise of the device. This vulnerability can be exploited by an
unauthenticated attacker under the device's default configuration.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-12935?


## How do I fix CVE-2026-12935?

No fix has been published for CVE-2026-12935 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12935 being exploited?

There is no known exploitation of CVE-2026-12935 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12935 and fix it if it is affected.

What it is: CVE-2026-12935 is a high-severity memory corruption vulnerability in TP-Link Systems Inc. TL-WR940N v6, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-12935 in the wild and no public exploit code.

Affected product: TP-Link Systems Inc. TL-WR940N v6. 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-2026-12935/ (Markdown: https://insights.sbomify.com/CVE-2026-12935/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12935
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12935
- OSV: https://osv.dev/vulnerability/CVE-2026-12935

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12935/
Summaries are generated and may contain mistakes; the official description above is the record.