parse-server's session object properties can be updated by foreign user if object ID is knownGHSA-6w4q-23cf-j9jp
MEDIUMFix: parse-community/parse-server@37fed30GHSA-6w4q-23cf-j9jp is a medium-severity (CVSS 4.3) CWE-669 vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.
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 GHSA-6w4q-23cf-j9jp.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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
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 | 4.10.15npm install parse-server@4.10.15 |
| 📦npm | parse-server | ≥ 5.0.0&&< 5.2.6 | 5.2.6npm install parse-server@5.2.6 |
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 4.10.15 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.
Frequently Asked Questions
Is GHSA-6w4q-23cf-j9jp in your dependencies?
Find it across npm, including transitive dependencies.