CVE-2026-32269: Parse Server OAuth2 adapter app ID validation sends wrong token to introspection endpoint

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-12 · updated 2026-06-17
Weakness: CWE-683

Description

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.13 and 8.6.39, the OAuth2 authentication adapter does not correctly validate app IDs when appidField and appIds are configured. During app ID validation, a malformed value is sent to the token introspection endpoint instead of the user's actual access token. Depending on the introspection endpoint's behavior, this could either cause all OAuth2 logins to fail, or allow authentication from disallowed app contexts if the endpoint returns valid-looking data for the malformed request. Deployments using the OAuth2 adapter with appidField and appIds configured are affected. This vulnerability is fixed in 9.6.0-alpha.13 and 8.6.39.

Affected products

parse-community parse-server: from 8.0.2 before 8.6.39; from 9.0.0 before 9.6.0; 9.6.0-alpha1, 9.6.0-alpha10, 9.6.0-alpha11, 9.6.0-alpha12, 9.6.0-alpha2, 9.6.0-alpha3 (+6) — fixed in 8.6.39, 9.6.0

How to fix

Upgrade to a fixed version: parse-community parse-server 8.6.39, 9.6.0. Check the vendor advisory for mitigations.

References

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