GHSA-79wj-8rqv-jvp5
parse-server's endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
parse-servernpmDescription
Impact
The readOnlyMasterKey can call POST /loginAs to obtain a valid session token for any user. This allows a read-only credential to impersonate arbitrary users with full read and write access to their data. Any Parse Server deployment that uses readOnlyMasterKey is affected.
Patches
The fix adds a check to the /logInAs handler.
Workarounds
There is no workaround other than not using readOnlyMasterKey.
References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-79wj-8rqv-jvp5
- Fix for Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.4
- Fix for Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.6
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | all versions | 8.6.6 |
| 📦npm | parse-server | ≥ 9.0.0&&< 9.5.0-alpha.4 | 9.5.0-alpha.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update parse-server to 8.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-79wj-8rqv-jvp5 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.
How O3 protects you
O3 pinpoints whether GHSA-79wj-8rqv-jvp5 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-79wj-8rqv-jvp5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-79wj-8rqv-jvp5 in your dependencies?
O3 detects GHSA-79wj-8rqv-jvp5 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.