Affected: Maven: com.fasterxml.jackson.core:jackson-databind, Maven: tools.jackson.core:jackson-databind

## Summary In `BeanDeserializer._deserializeUsingPropertyBased`, the active-view (`@JsonView`) filter was applied only to creator properties; the regular property-buffering branch performed no `prop.visibleInView(activeView)` check. A change making `SetterlessProperty.isMerging()` return `true` routed setterless Collection/Map properties through this unguarded path, so a setterless collection annotated with a restricted `@JsonView` is populated from attacker JSON even when the active view excludes it.

## Impact View-restricted (e.g. admin-only) setterless collection/map properties can be written from untrusted JSON despite `@JsonView` gating — an access-control / mass-assignment bypass. No RCE or DoS.

## Affected / Patched (verified via `git tag --contains`) - 2.21 line: `>= 2.21.0, < 2.21.4` -> fixed in **2.21.4** (backport `94c5d21`, #5970) - 3.x line: `>= 3.0.0, < 3.1.4` -> fixed in **3.1.4** (#5969, `5bf23ed`)

## Severity / CWE Maintainer: minor. Reporter: HIGH. CWE-863 (Incorrect Authorization); related CWE-1220.

## Credits Omkhar Arasaratnam (@omkhar) - finder.