CVE-2026-103863

Unknown

Description

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Apache Sling Engine. Content-Type, charset, and redirect changes from an included component evade the protectheaders / checkcontenttype enforcement through setHeader(), repeated calls to setContentType(), the charset APIs, Servlet 6.1 redirect overloads, and stale config - enabling stored XSS despite enabled protections. This issue affects Apache Sling Engine before 3.0.4. Users are recommended to upgrade to version 3.0.4, which fixes the issue.

SeverityUnknown

CVSS—

Exploit probability—

ProductApache Sling Engine

PublishedNov 5, 2026

First seenNov 5, 2026

Weakness typeCWE-79Cross-site scripting (XSS)CWE-693CWE-693

How to fix

Update

Apache Software Foundation Apache Sling Engine3.0.4 or later

Vendor advisories

lists.apache.org/thread.html/rll7kjtbpj2lvh4nzmrw5sdmqww64ldg

Affected products

Product	Affected versions	Fixed in
Apache Software Foundation Apache Sling Engine	v < 3.0.4	3.0.4

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