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zeep: forbid_external not enforced (SSRF) fixed in 4.3.3

In python-zeep versions 4.0.0 through 4.3.2, the `forbid_external` setting was defined but not enforced, allowing SSRF via transitive fetching of external resou

20 Jun 2026Read 1 minSeverity: schedule it

What changed

In python-zeep versions 4.0.0 through 4.3.2, the `forbid_external` setting was defined but not enforced, allowing SSRF via transitive fetching of external resources in WSDL/XSD documents. Fixed in 4.3.3 where `forbid_external=True` now blocks such fetches.

Who it affects

Applications using python-zeep 4.0.0 to 4.3.2 that load untrusted WSDL/XSD documents or rely on `forbid_external=True` for security.

What to do today

Upgrade to python-zeep 4.3.3 or later and set `forbid_external=True` when loading documents from untrusted sources.

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