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PatchSiren cyber security CVE debrief

CVE-2026-21826 HCLSoftware CVE debrief

CVE-2026-21826 is a medium-severity vulnerability affecting HCL Digital Experience and HCL Digital Experience Compose. The vulnerability is caused by a Host header injection issue, which allows an attacker to manipulate the Host header and cause the application to behave in unexpected ways. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 6.1. The vulnerability was published on 2026-06-05 and last modified on 2026-06-10.

Vendor
HCLSoftware
Product
Digital Experience & DX Compose
CVSS
MEDIUM 6.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-07-23
Advisory published
2026-06-05
Advisory updated
2026-07-23

Who should care

Administrators and users of HCL Digital Experience and HCL Digital Experience Compose should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability is caused by a Host header injection issue in HCL Digital Experience and HCL Digital Experience Compose. This allows an attacker to manipulate the Host header and cause the application to behave in unexpected ways.

Defensive priority

Medium

Recommended defensive actions

  • Apply patches or updates provided by the vendor to fix the vulnerability.
  • Restrict access to the affected systems and monitor for suspicious activity.
  • Implement additional security measures such as web application firewalls (WAFs) to detect and prevent attacks.

Evidence notes

The vulnerability is described in the CVE record and the NVD detail page. The vendor has provided a mitigation or vendor reference.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-21826 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-21826

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-21826 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-21826

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.