fix: Cloud Code beforeFind trigger context is not isolated from prototype pollution

[mtrezza]

Issue

The beforeFind trigger context is not isolated from Object.prototype, unlike every other Cloud Code trigger. getRequestObject builds the trigger context with a null prototype (Object.assign(Object.create(null), context)), but the symmetric getRequestQueryObject used by beforeFind still assigned context: context || {}, so its request.context inherited Object.prototype.

Tasks

• Add tests

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[coderabbitai]

📝 Walkthrough

Walkthrough

Query trigger contexts are now created with null prototypes to prevent prototype pollution, and mutations made during beforeFind are propagated to the shared context used by afterFind. Regression tests cover isolation, pollution resistance, and mutation propagation.

Changes

Query trigger context isolation

Layer / File(s)	Summary
Null-prototype context construction src/triggers.js, spec/vulnerabilities.spec.js	Query trigger contexts use null-prototype objects, with tests verifying no inherited or polluted properties are exposed.
Mutation propagation between triggers src/triggers.js, spec/vulnerabilities.spec.js	Mutations made in beforeFind are copied into the afterFind context while both contexts retain null prototypes.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• parse-community/parse-server#10352: Also hardens Cloud Code trigger contexts against prototype pollution.
• parse-community/parse-server#8480: Also modifies trigger request construction in src/triggers.js.

Suggested reviewers: Moumouls

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Caution

Pre-merge checks failed

Please resolve all errors before merging. Addressing warnings is optional.

• Ignore

❌ Failed checks (1 error, 1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❌ Error	The PR description is missing the required Issue, Approach, and Tasks sections.	Add the template sections with an issue reference, a brief approach summary, and completed task checkboxes relevant to this PR.
Security Check	⚠️ Warning	Object.assign(context, requestObject.context) can turn a user-supplied __proto__ key into prototype pollution on the shared context object.	Merge back only safe own keys or keep the shared context null-prototype too; never Object.assign untrusted keys into a plain object.
Engage In Review Feedback	❓ Inconclusive	Repo shows only code/test changes in one commit; no review-thread or comment history is available to verify engagement with feedback.	Provide the PR review thread or GitHub comments so I can confirm whether feedback was discussed before being resolved.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title matches the required prefix and clearly describes the main fix.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.68%. Comparing base (cb9b542) to head (c599875).
⚠️ Report is 1 commits behind head on alpha.

Additional details and impacted files

@@           Coverage Diff           @@
##            alpha   #10570   +/-   ##
=======================================
  Coverage   92.67%   92.68%           
=======================================
  Files         193      193           
  Lines       17007    17009    +2     
  Branches      248      248           
=======================================
+ Hits        15762    15764    +2     
  Misses       1224     1224           
  Partials       21       21           

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[parseplatformorg]

🎉 This change has been released in version 9.10.0-alpha.7