CVE-2026-21788 HCL Connections is vulnerable to cross-site scripting (XSS)
An attacker can execute arbitrary script code in a user's browser to steal authentication credentials and compromise accounts in HCL Connections.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-21788?
CVE-2026-21788 is a medium-severity cross-site scripting vulnerability in HCLSoftware Connections, published on 19 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
HCL Connections is vulnerable to a cross-site scripting attack where an attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user which leads to executing malicious script code. This may allow the attacker steal cookie-based authentication credentials and comprise user's account then launch other attacks.
Weakness: CWE-79
Which versions are affected by CVE-2026-21788?
It affects 1 product.
Products include Hcltech Connections.
How do I fix CVE-2026-21788?
No fix has been published for CVE-2026-21788 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-2026-21788 being exploited?
There is no known exploitation of CVE-2026-21788 in the wild and no public exploit code.
Other vulnerabilities in HCLSoftware Connections
- CVE-2020-4085 Information disclosure in "HCL Connections"
- CVE-2019-4209 Open redirect in HCL Connections
- CVE-2023-28018 HCL Connections s vulnerable to possible denial of service for certain users
- CVE-2020-4083 Information disclosure in "HCL Connections"
- CVE-2024-30112 HCL Connections is vulnerable to a cross-site scripting (XSS) vulnerability
Sources
Also known as GHSA-p5wg-ghxx-734q.