CVE-2026-30965

Description

### 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

How to fix CVE-2026-30965

To remediate CVE-2026-30965, upgrade the affected package to a fixed version below.

—upgrade to 8.6.21 or later
—upgrade to 9.5.2-alpha.8 or later

Is CVE-2026-30965 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

from 0, < 8.6.21, >= 9.0.0, < 9.5.2
>= 9.0.0-alpha.1, < 9.5.2-alpha.8

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 4.0	—	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N