CVE-2026-40457 Reflected XSS in LMS
Attackers can inject arbitrary JavaScript via crafted links in LMS, potentially leading to session hijacking or malicious actions when authenticated users click them.
- 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-2026-40457?
CVE-2026-40457 is a low-severity cross-site scripting vulnerability in LMS, published on 18 Jun 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
A Reflected Cross-Site Scripting (XSS) vulnerability exists in LMS (LAN Management System) before commit 9c5651b in the "dbrecover.php" and "netremap.php" modules where unsanitized GET parameters are directly embedded into HTML output. This allows an attacker to inject arbitrary JavaScript when an authenticated user clicks a crafted link, provided the required conditions (such as a network defined in the system) are met.
Weakness: CWE-79
Which versions are affected by CVE-2026-40457?
How do I fix CVE-2026-40457?
No fix has been published for CVE-2026-40457 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-40457 being exploited?
There is no known exploitation of CVE-2026-40457 in the wild and no public exploit code.
Sources
Also known as GHSA-3vrh-xvg4-68rm.