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TI-2026-15145 Aliases CVE-2026-18430

HumHub 1.18.4 - Stored XSS in comment-deletion notifications through unescaped administrator reason

Priority HIGH 67CWE-79Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

HumHub 1.18.4 contains a stored cross-site scripting vulnerability in the comment-deletion notification flow. A Space administrator can delete another user's comment, choose to notify the original author, and place HTML/JavaScript in the deletion reason.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00466 40th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
humhubHumHub1.18.4—No fix listedCNA
  • HumHub Vendorhumhub Affected 1.18.4 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:humhub:humhub:*:*:*:*:*:*:*:*——humhub
  • cpe:2.3:a:humhub:humhub:*:*:*:*:*:*:*:* Versions — — ·humhub

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-18430

References

Patch 1

Advisory 1

Other 1

  • TI-2022-08676 Improper access control in humhub CVSS 3.1MEDIUM 6.5
  • TI-2017-14097 HumHub Reflected cross site scriting CVSS 3.1MEDIUM 6.1
  • TI-2025-34545 Files: Potential for SQL Injection through File Browse and List Operations CVSS 4.0CRITICAL 9.2
  • TI-2017-14099 HumHub privileges management CVSS 3.1CRITICAL 9.8
  • TI-2024-34921 User enumeration in HubHub CVSS 4.0MEDIUM 6.9
  • TI-2014-07750 SQL injection vulnerability in the actionIndex function in… CVSS 2.0HIGH 7.5
See all 24 →

Sources

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