# CVE-2026-103863: Apache Sling Engine: Include-protection mitigations bypassable via uncovered response-wrapper paths

Status: published. Published: 2026-11-05. Updated: 2026-11-05.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Apache Software Foundation / Apache Sling Engine: ≥ 0; < 3.0.4 (affected, semver). Source: CNA: apache

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-79, CWE-693

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://lists.apache.org/thread.html/rll7kjtbpj2lvh4nzmrw5sdmqww64ldg (CNA: apache; vendor-advisory)

## Provenance

- CNA: apache: https://www.cve.org/CVERecord?id=CVE-2026-103863; retrieved 2026-11-05; source updated 2026-11-05

Revision: 873895ef764bda663f9231aa04a8d4800fc2065f96e4ff72d6ada3b75ad7b714

Canonical: https://y2.dev/cve/CVE-2026-103863

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