CVE-2026-21718 Copeland XWEB and XWEB Pro Use of a Broken or Risky Cryptographic Algorithm

Critical 10.0 Published 27 Feb 2026 Updated 2 Mar 2026

Attackers can bypass authentication via weak cryptography to execute code on Copeland XWEB systems, requiring immediate patching for industrial control security.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-21718?

CVE-2026-21718 is a critical vulnerability in Copeland XWEB 300D PRO, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An authentication bypass vulnerability exists in Copeland XWEB Pro version 1.12.1 and prior, enabling any attackers to bypass the authentication requirement and achieve pre-authenticated code execution on the system.

Weakness: CWE-327

Which versions are affected by CVE-2026-21718?

It affects 3 products.

Products include Copeland Xweb 300d Pro Firmware, Copeland Xweb 500b Pro Firmware, Copeland Xweb 500d Pro Firmware.

How do I fix CVE-2026-21718?

No fix has been published for CVE-2026-21718 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-21718 being exploited?

There is no known exploitation of CVE-2026-21718 in the wild and no public exploit code.

Sources

Also known as GHSA-7r34-g88h-g49f.