GHSA-mhm7-754m-9p8w: jackson-databind: `@JsonView` bypass for creator properties with `@JsonTypeInfo(include=As.EXTERNAL_PROPERTY)`

Summary In BeanDeserializer.deserializeUsingPropertyBasedWithExternalTypeId, the active-view (@JsonView) filter was applied only to the regular bean-property branch; the creator-property branch performed no creatorProp.visibleInView(activeView) check. A constructor parameter annotated with both @JsonView(RestrictedView.class) and `@JsonTypeInfo(use=Id.NAME, include=As.EXTERNAL_PROPERTY)` is populated from attacker JSON even when a more restrictive view is active. This is a patch gap. GHSA-5hh8 (CVE-2026-54517) and GHSA-rcqc (CVE-2026-54518) descriptions cover only the main property-based path and the unwrapped-creator path respectively; the external-type-id creator path was fixed on the 3.x line via #6004 ("Extend #5969/#5971 fixes to ... external-type-id case in regular BeanDeserializer", commit 7dc7a17, 2026-05-22) but the fix was never backported to 2.21 or 2.18. Users on 2.21.4 and 2.18.8 who upgraded per the published advisories remain vulnerable to the same @JsonView bypass technique via a different code path. Vulnerable Code Path File: com/fasterxml/jackson/databind/deser/BeanDeserializer.java Method: deserializeUsingPropertyBasedWithExternalTypeId On 2.21.4 (and 2.18.8), the creator-property branch (around line 1125-1158) checks creatorProp.isInjectionOnly() and hands off to ext.handlePropertyValue(...) / buffer.assignParameter(...) without ever consulting visibleInView(activeView): if (creatorProp != null) { // [databind#1381]: if useInput=FALSE, skip deserialization from input if (creatorProp.isInjectionOnly()) { ... } // NO visibleInView(activeView) CHECK HERE if (!ext.handlePropertyValue(p, ctxt, propName, null)) { if (buffer.assignParameter(creatorProp, ...)) { ... } } continue; } On 3.1.4, the same branch contains the additional guard (commit 7dc7a17): if (creatorProp != null) { // [databind#5971]: must honor active view here too if ((activeView != null) && !creatorProp.visibleInView(activeView)) { p.skipChildren(); continue; } ... } The 2.21