GHSA-6r2j-cxgf-495f
Parse Server vulnerable to session token exfiltration via `redirectClassNameForKey` query parameter
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | parse-server | >= 9.0.0-alpha.1, < 9.5.2-alpha.8 | 9.5.2-alpha.8 |
| npm | parse-server | < 8.6.21 | 8.6.21 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
A vulnerability in Parse Server's query handling allows an authenticated or unauthenticated attacker to exfiltrate session tokens of other users by exploiting the `redirectClassNameForKey` query parameter. Exfiltrated session tokens can be used to take over user accounts.
The vulnerability requires the attacker to be able to create or update an object with a new relation field, which depends on the Class-Level Permissions of at least one class.
### Patches
The fix applies the same security checks that normally protect class access after the query redirect, ensuring that queries redirected via `redirectClassNameForKey` are subject to the same restrictions as direct queries to the target class.
### Workarounds
Set restrictive Class-Level Permissions to prevent clients from creating new fields on classes, specifically by disabling `addField` for public access and unauthenticated users. Note that this limits client functionality and does not fully eliminate the risk if a relation field pointing to a protected class already exists in the schema.
### References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-6r2j-cxgf-495f
- Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.8
- Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.21
References
External links from the advisory. They lead to third-party sites.
- https://github.com/parse-community/parse-server/security/advisories/GHSA-6r2j-cxgf-495f
- https://nvd.nist.gov/vuln/detail/CVE-2026-30965
- https://github.com/parse-community/parse-server
- https://github.com/parse-community/parse-server/releases/tag/8.6.21
- https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.8