Skip to content
KSEF-BUS-202 SECURITY Error Gov Enforced

XML processing instructions forbidden

Instrukcje przetwarzania XML (processing instructions)

Problem

XML document contains a processing instruction (e.g., <?xml-stylesheet ...?>, <?php ...?>). KSeF does not accept processing instructions — the only allowed <?...?> element is the XML declaration.

How to Fix

Remove processing instructions from the XML file. Only the declaration <?xml version="1.0" encoding="UTF-8"?> is allowed.

Source Reference

KSeF Guard security guard (W3C XML 1.0 §2.6 PI production; KSeF API empirical rejection)

View source

Source Quote

“KSeF rejects XML documents containing processing instructions other than the XML declaration (<?xml ...?>).”
Description SHA-256: 54dd5ce6e9fb…

Justification

FORMAT

Legal Basis Chain

1

Processing instructions in XML 1.0

Instrukcje przetwarzania w XML 1.0

“PI ::= '<?' PITarget (S (Char* - (Char* '?>' Char*)))? '?>'”
W3C XML 1.0 (Fifth Edition), Section 2.6
2

KSeF — empirical PI rejection

KSeF — empiryczne odrzucenie PI

“KSeF Guard conformance testing confirms that documents containing processing instructions (other than the XML declaration) are rejected by KSeF — typical attack vectors are xml-stylesheet and php.”
KSeF Guard conformance testing (empirical)