# CVE-2026-109506: Improper Authentication in Multiple TP-Link WiFi Repeaters

> An attacker on the local network can bypass authentication on TP-Link repeaters by deriving credentials from captured HTTP traffic, gaining admin access.

- **Severity:** Medium 5.9 (`CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-v8j9-72vh-g46g

## What is CVE-2026-109506?

CVE-2026-109506 is a medium-severity authentication bypass vulnerability in TP-Link Systems Inc. RE190 v5, published on 14 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Multiple
TP-Link Wi-Fi range extenders use a custom, reversible XOR-and-dictionary
transformation in the HTTP web-management login flow. An unauthenticated attacker
on the same local network who can capture the network traffic associated with
legitimate administrator login may be able to derive an alternative credential
value that produces the same accepted authentication result and use it to
authenticate to the device’s web-management interface with administrator
privileges. Exploitation requires the management login to use HTTP and the
attacker to observe the session key, dictionary, and login value associated
with a legitimate administrator login.

Successful
exploitation may allow an unauthenticated adjacent attacker to gain
administrator access to the affected device and modify exposed configuration
settings.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-109506?


## How do I fix CVE-2026-109506?

No fix has been published for CVE-2026-109506 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109506 being exploited?

There is no known exploitation of CVE-2026-109506 in the wild and no public exploit code.

Public exploit code:

- Technical writeup of CVE-2026-109506, a vulnerability I found in multiple TP-Link Wi-Fi Range Extenders (github_poc): https://github.com/lukaspalm/CVE-2026-109506

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109506 and fix it if it is affected.

What it is: CVE-2026-109506 is a medium-severity authentication bypass vulnerability in TP-Link Systems Inc. RE190 v5, published on 14 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-109506 in the wild and no public exploit code.

Affected product: TP-Link Systems Inc. RE190 v5. 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-2026-109506/ (Markdown: https://insights.sbomify.com/CVE-2026-109506/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109506
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109506
- OSV: https://osv.dev/vulnerability/CVE-2026-109506

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-109506/
Summaries are generated and may contain mistakes; the official description above is the record.