CVE-2026-30965CWE-863

Parse Server session token exfiltration via `redirectClassNameForKey` query parameter

Critical · published March 10, 2026

CVSS v4.0
9.9
EPSS
2%
Percentile
75.0
In the wild
Unconfirmed
What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.8 and 8.6.21, 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. This vulnerability is fixed in 9.5.2-alpha.8 and 8.6.21.

The record
Technical detail
CVSS v4.0
9.9 · CRITICAL
Vector
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
EPSS
0.01555 · 75.0th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2026-03-10T20:43Z
EPSS history
Timeline
  • 10 MAR 20:43Z
    Parse Server session token exfiltration via `redirectClassNameForKey` query parameter
    cvelistv5