CVE-2021-41109 is a high-severity (CVSS 7.5) Information Exposure vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.
LiveQuery publishes user session tokens in parse-server
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-41109 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to version 4.10.4, for regular (non-LiveQuery) queries, the session token is removed from the response, but for LiveQuery payloads it is currently not. If a user has a LiveQuery subscription on the Parse.User class, all session tokens created during user sign-ups will be broadcast as part of the LiveQuery payload. A patch in version 4.10.4 removes session tokens from the LiveQuery payload. As a workaround, set user.acl(new Parse.ACL()) in a beforeSave trigger to make the user private already on sign-up.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | all versions | 4.10.4npm install parse-server@4.10.4 |
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 4.10.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41109 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2021-41109 in your dependencies?
Find it across npm, including transitive dependencies.