Apache Sling Engine parameter parser enables HTTP request smuggling
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
Apache Sling Engine before 3.0.4 contains a flaw in its query and form parameter parser. The parser accepts non-standard percent-escapes and wrong charsets and keeps processing requests after such errors, so it interprets HTTP requests differently from standard parsers (CWE-444). This inconsistent interpretation enables HTTP request smuggling.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
Inconsistent interpretation of HTTP requests ('HTTP Request/Response smuggling') vulnerability in Apache Sling Engine. The engine's query/form parser accepts non-standard percent-escapes, wrong charsets, and continues request processing on such errors. This issue affects Apache Sling Engine: before 3.0.4. Users are recommended to upgrade to version 3.0.4, which fixes the issue.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade Apache Sling Engine to version 3.0.4, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
- Fix · CNA Apache Sling Engine (Apache Software Foundation) Fixed in 3.0.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Apache Sling Engine 3.0.4
3 records Highest priority Priority LOW 3 LOW
Other records, highest priority first
- TI-2026-85398 Log injection in Apache Sling Engine via unneutralized request valuesPriority LOW 22
- TI-2026-85397 Cross-site scripting bypasses protections in Apache Sling EnginePriority LOW 22
Vendor assessments
Timeline
- 2026-11-05 Threatist record created from CVE-2026-103866
- 2026-11-05 Alias added: GHSA-fh7f-x3gj-j2vv
- 2026-11-07 Affected versions changed · Red Hat
- 2026-11-07 CVSS score added · Red Hat
References
More Apache vulnerabilities
- TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
- TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
- TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
- TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
- TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-103866 · CVE Program
- CVE-2026-103866 · NVD
- FIRST EPSS
- GHSA-fh7f-x3gj-j2vv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-103866 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences