# CVE-2026-12222: Yealink SIP-T46U Web FastCGI Service bttest mod_webd.BlueToothTest stack-based overflow

> A stack-based buffer overflow in the Yealink SIP-T46U web service allows local network attackers to execute arbitrary code or cause denial of service.

- **Severity:** High 8.6 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jun 2026
- **Updated:** 27 Jun 2026
- **Also known as:** GHSA-3c47-ghg7-jxpp

## What is CVE-2026-12222?

CVE-2026-12222 is a high-severity memory corruption vulnerability in Yealink SIP-T46U, published on 15 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was determined in Yealink SIP-T46U 108.86.0.118. Affected is the function mod_webd.BlueToothTest of the file /api/inner/bttest of the component Web FastCGI Service. Executing a manipulation of the argument btMac/pin/reserved can lead to stack-based buffer overflow. The attack needs to be done within the local network. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure and is working on a patch to fix it.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-12222?


## How do I fix CVE-2026-12222?

No fix has been published for CVE-2026-12222 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12222 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-12222 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12222 and fix it if it is affected.

What it is: CVE-2026-12222 is a high-severity memory corruption vulnerability in Yealink SIP-T46U, published on 15 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-12222 exists.

Affected product: Yealink SIP-T46U. 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-2026-12222/ (Markdown: https://insights.sbomify.com/CVE-2026-12222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12222
- OSV: https://osv.dev/vulnerability/CVE-2026-12222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12222/
Summaries are generated and may contain mistakes; the official description above is the record.