# CVE-2025-40710: Host Header Injection (HHI) in the Hotspot Shield VPN client

> Attackers can manipulate Host headers to redirect VPN traffic to malicious servers, potentially exposing user data or bypassing security controls.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:L/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:** 30 Jun 2025
- **Updated:** 30 Jun 2025
- **Also known as:** GHSA-vhmg-x9mc-q29w

## What is CVE-2025-40710?

CVE-2025-40710 is a low-severity vulnerability in Hotspot Shield VPN client, published on 30 Jun 2025. 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

Host Header Injection (HHI) vulnerability in the Hotspot Shield VPN client, which can induce unexpected behaviour when accessing third-party web applications through the VPN tunnel. Although such applications do not present this vulnerability per se, the use of the tunnel, together with a forged Host header, can cause the VPN client to redirect or forward HTTP requests to servers other than those originally intended, leading to consequences such as open redirects or delivery of traffic to infrastructure controlled by an attacker. This does not imply a flaw in the target applications, but in how the VPN client internally handles outgoing headers and requests.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2025-40710?


## How do I fix CVE-2025-40710?

No fix has been published for CVE-2025-40710 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-40710 being exploited?

There is no known exploitation of CVE-2025-40710 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40710 and fix it if it is affected.

What it is: CVE-2025-40710 is a low-severity vulnerability in Hotspot Shield VPN client, published on 30 Jun 2025. 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-2025-40710 in the wild and no public exploit code.

Affected product: Hotspot Shield VPN client. 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-2025-40710/ (Markdown: https://insights.sbomify.com/CVE-2025-40710/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40710
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40710
- OSV: https://osv.dev/vulnerability/CVE-2025-40710

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40710/
Summaries are generated and may contain mistakes; the official description above is the record.