GHSA-6w4q-23cf-j9jp
MEDIUMparse-server's session object properties can be updated by foreign user if object ID is known
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
A foreign user can write to the session object of another user if the session object ID is known. For example, a foreign user can assign the session object to their own user by writing to the user field and then read any custom fields of that session object.
Note that assigning a session to a foreign user does not usually change the privileges of neither of the two users, according to how Parse Server uses session objects internally. However, if custom logic is used to relate specific session objects to privileges this vulnerability may have a higher level of severity.
The vulnerability does not allow a foreign user to assign a session object to themselves, read the session token, and then reassign the session object to the original user to then authenticate as that user with the known session token. The vulnerability only exists for foreign session objects, a user cannot assign their own session to another user.
While it is unlikely that the session object ID of another user is known, it is possible to brute-force guess an object ID, even though the attacker would not know to which user a successfully guessed session object ID belongs.
Patches
The fix prevents writing to foreign session objects, even if the session object ID is known.
Workarounds
Add a beforeSave trigger to the _Session class and prevent writing if the requesting user is different from the user in the session object.
References
- GitHub advisory GHSA-6w4q-23cf-j9jp
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | all versions | 4.10.15 |
| 📦npm | parse-server | ≥ 5.0.0&&< 5.2.6 | 5.2.6 |
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 4.10.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6w4q-23cf-j9jp 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-6w4q-23cf-j9jp 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-6w4q-23cf-j9jp. 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-6w4q-23cf-j9jp in your dependencies?
O3 detects GHSA-6w4q-23cf-j9jp across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.