CVE-2026-21788 | HCL Connections is vulnerable to cross-site scripting (XSS)

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.

Published: 2026-03-19 Last update: 2026-03-19 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-21788 is rated Low Risk (27.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21788

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-26 0.04% 0.05% +0.01%
2 2026-03-19 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21788

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.3 2.7 [email protected]

Weakness enumeration for CVE-2026-21788

Affected software / configurations for CVE-2026-21788

Vendor Product Version Raw CPE
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:-:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release1:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release10:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release11:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release12:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release2:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release3:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release4:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release5:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release6:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release7:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release8:*:*:*:*:*:*
hcltech connections 8.0 cpe:2.3:a:hcltech:connections:8.0:cumulative_release9:*:*:*:*:*:*

References for CVE-2026-21788

cvelogic Threat Intelligence