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TI-2021-18888 Aliases CVE-2021-42656GHSA-2xwp-7j3p-c78x

SiteServer CMS V6.15.51 is affected by a Cross Site Scripting (XSS) vulnerability.

Priority LOW 26CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

SiteServer CMS V6.15.51 is affected by a Cross Site Scripting (XSS) vulnerability.

Why it matters now

EPSS 0.00712 53rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
—SSCMS (NuGet)up to 6.15.51—No fix listedGHSA-2xwp-7j3p-c78x
  • — Vendor— Affected all versions Fixed in — No fix listed CNA
  • SSCMS (NuGet) Vendor— Affected up to 6.15.51 Fixed in — No fix listed GHSA-2xwp-7j3p-c78x

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:sscms:siteserver_cms:6.15.51:*:*:*:*:*:*:*6.15.51VulnerableSscms
  • cpe:2.3:a:sscms:siteserver_cms:6.15.51:*:*:*:*:*:*:* Versions 6.15.51 Vulnerable ·Sscms

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-42656
  2. 2026-10-03 Alias added: GHSA-2xwp-7j3p-c78x

References

Exploit 1

Patch 1

Advisory 2

  • TI-2022-21766 SiteServer CMS 7.1.3 is vulnerable to SQL Injection. CVSS 3.1CRITICAL 9.8
  • TI-2022-21765 SiteServer CMS 7.1.3 has a SQL injection vulnerability the background. CVSS 3.1CRITICAL 9.8
  • TI-2025-28799 An arbitrary file read vulnerability in the ReadTextAsynchronous function of SSCMS v7.3.1… CVSS 3.1HIGH 7.1
  • TI-2022-10923 SiteServer CMS v7.x allows attackers to execute arbitrary code via a crafted plug-in. CVSS 3.1CRITICAL 9.8
  • TI-2021-18886 SiteServer CMS < V5.1 is affected by an unrestricted upload of a file with dangerous type… CVSS 3.1CRITICAL 9.8
  • TI-2021-18887 SiteServer CMS V6.15.51 is affected by a SQL injection vulnerability. CVSS 3.1HIGH 8.8
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences