CVE-2026-32242: Parse Server OAuth2 adapter shares mutable state across providers via singleton instance
Impact
Parse Server's built-in OAuth2 auth adapter exports a singleton instance that is reused directly across all OAuth2 provider configurations. Under concurrent authentication requests for different OAuth2 providers, one provider's token validation may execute using another provider's configuration, potentially allowing a token that should be rejected by one provider to be accepted because it is validated against a different provider's policy.
Deployments that configure multiple OAuth2 providers via the oauth2: true flag are affected.
Patches
The fix ensures that a new adapter instance is created for each provider instead of reusing the singleton, so each provider's configuration is isolated.
Workarounds
There is no known workaround. If only a single OAuth2 provider is configured, the race condition cannot occur.
References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-2cjm-2gwv-m892 - Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.11 - Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.37
Other sources
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.11 and 8.6.37, Parse Server's built-in OAuth2 auth adapter exports a singleton instance that is reused directly across all OAuth2 provider configurations. Under concurrent authentication requests for different OAuth2 providers, one provider's token validation may execute using another provider's configuration, potentially allowing a token that should be rejected by one provider to be accepted because it is validated against a different provider's policy. Deployments that configure multiple OAuth2 providers via the oauth2: true flag are affected. This vulnerability is fixed in 9.6.0-alpha.11 and 8.6.37.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-32242?
CVE-2026-32242 is classified as a high severity vulnerability affecting the Parse Server authentication system.
How do I fix CVE-2026-32242?
To fix CVE-2026-32242, upgrade your Parse Server to version 8.6.37 or 9.6.0-alpha.11 or later.
What software is affected by CVE-2026-32242?
CVE-2026-32242 affects all versions of Parse Server prior to 8.6.37 and between 9.0.0 and 9.6.0-alpha.11.
What is the impact of CVE-2026-32242?
The impact of CVE-2026-32242 is that it allows concurrent authentication requests to improperly share configuration, leading to potential security breaches.
Is there a workaround for CVE-2026-32242?
There is no recommended workaround for CVE-2026-32242; the best course of action is to apply the necessary updates.