Apache Sling XSS: Improper escaping in the XSS Webconsole plugin (CVE-2026-91999) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-91999

Apache Sling XSS: Improper escaping in the XSS Webconsole plugin

Answer in brief

CVE-2026-91999 records a Unknown severity vulnerability in Apache Sling XSS: Improper escaping in the XSS Webconsole plugin. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/Apache Sling XSS (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 Sep 23, 2026Updated Sep 23, 2026Source checked Sep 23, 2026First seen by HOL Sep 23, 2026Material review Sep 23, 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: Available

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 Apache Software Foundation/Apache Sling XSS (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Apache Software Foundation/Apache Sling XSSgeneric	>=0 <2.4.12	2.4.12

Recommended response

Check inventory. Check lockfiles and deployed manifests for Apache Software Foundation/Apache Sling XSS.
Review the reported fix. Update Apache Software Foundation/Apache Sling XSS to 2.4.12 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 23, 2026

Sources and claim methodology

Source referencelists.apache.org

Upstream source description

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Apache Sling XSS. This issue affects Apache Sling XSS: before 2.4.12. Users are recommended to upgrade to version 2.4.12, which fixes the issue.

Quoted source text, attributed separately from HOL analysis.