CVE-2026-32878 — parse-server
Fix: parse-community/parse-server#10200CVE-2026-32878 is a CWE-1321 vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.
Parse Server vulnerable to schema poisoning via prototype pollution in deep copy
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32878.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
parse-servernpmDescription
Impact
An attacker can bypass the default request keyword denylist protection and the class-level permission for adding fields by sending a crafted request that exploits prototype pollution in the deep copy mechanism. This allows injecting fields into class schemas that have field addition locked down, and can cause permanent schema type conflicts that cannot be resolved even with the master key.
Patches
The vulnerable third-party deep copy library has been replaced with a built-in deep clone mechanism that handles prototype properties safely, allowing the existing denylist check to correctly detect and reject the prohibited keyword.
Workarounds
None.
Vulnerability Independence
This vulnerability is not caused by or dependent on a vulnerability in a third-party dependency.
The third-party deepcopy library that was replaced in the fix has no known CVE or security advisory regarding this. The library functions as designed. It is not vulnerable.
The vulnerability is in parse-server's own request processing logic. Parse-server's security-critical keyword denylist check runs after the deep copy step in the request pipeline. The deep copy step strips __proto__ properties as a normal part of its cloning behavior, which means the denylist check never sees the prohibited key. This allows an attacker to bypass both the denylist protection and class-level permissions for adding fields, resulting in schema poisoning.
The root cause is parse-server's reliance on a cloning mechanism that alters the shape of the data before the security check can inspect it. This is a logic flaw in parse-server's security pipeline, not a vulnerability in a dependency. Replacing the cloning mechanism was the fix for parse-server's own bug.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | ≥ 9.0.0&&< 9.6.0-alpha.20 | 9.6.0-alpha.20npm install parse-server@9.6.0-alpha.20 |
| 📦npm | parse-server | all versions | 8.6.44npm install parse-server@8.6.44 |
Affected Products
parse-serverparseplatformDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update parse-server to 9.6.0-alpha.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32878 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-32878 in your dependencies?
Find it across npm, including transitive dependencies.