HumHub 1.18.4 - Stored XSS in comment-deletion notifications through unescaped administrator reason (CVE-2026-18430) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-18430

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

Answer in brief

CVE-2026-18430 records a Unknown severity vulnerability in HumHub 1.18.4 - Stored XSS in comment-deletion notifications through unescaped administrator reason. The current sources do not mark it as known exploited. The current feed maps HumHub/HumHub (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps HumHub/HumHub (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
HumHub/HumHubgeneric	1.18.4	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for HumHub/HumHub.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.