Parse Server session creation endpoint allows overwriting server-generated session fields

Description

An authenticated user can overwrite server-generated session fields (sessionToken, expiresAt, createdWith) when creating a session object via POST /classes/_Session. This allows bypassing the server’s session expiration policy by setting an arbitrary far-future expiration date. It also allows setting a predictable session token value.

Recommendation

Update the parse-server package to the latest compatible version. Followings are version details:

• Affected version(s): **< 8.6.42

  >= 9.0.0, < 9.6.0-alpha.17**

• Patched version(s): **8.6.42

  9.6.0-alpha.17**

References

• GHSA-5v7g-9h8f-8pgg
• CVE-2026-32742
• CWE-915
• CAPEC-310
• OWASP 2021-A6
• OWASP 2021-A8

Related Issues

• Parse Server's Session Update endpoint allows overwriting server-generated session fields - CVE-2026-33527
• parse-server's endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user - CVE-2026-30229
• Parse Server vulnerable to session token exfiltration via `redirectClassNameForKey` query parameter - CVE-2026-30965
• Parse Server has a protected fields bypass via dot-notation in query and sort - CVE-2026-31872

Tags:

npm

parse-server