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.
- 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
- None listed
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
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.
Sources
Also known as GHSA-vhmg-x9mc-q29w.