HOMEVULNERABILITIESCVE-2026-21788
MEDIUM

CVE-2026-21788

CWE-79Published: March 19, 2026· Updated: Mar 19, 2026

5.4
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:11.5th

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.

NVD Source

Technical Analysis

CVE-2026-21788 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionRequired
ScopeChanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected Vendors & Products

hcltech1 product
connections
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (1)

Quick Facts

CVE IDCVE-2026-21788
CVSS Score5.4 / 10
SeverityMEDIUM
WeaknessCWE-79
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 19, 2026

Related CVEs (CWE-79)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2026-21788 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.