CVE-2026-30229CWE-863

Parse Server: Endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user

High · published March 6, 2026

CVSS v4.0
8.5
EPSS
1%
Percentile
47.8
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 versions 8.6.6 and 9.5.0-alpha.4, the readOnlyMasterKey can call POST /loginAs to obtain a valid session token for any user. This allows a read-only credential to impersonate arbitrary users with full read and write access to their data. Any Parse Server deployment that uses readOnlyMasterKey is affected. This issue has been patched in versions 8.6.6 and 9.5.0-alpha.4.

The record
Technical detail
CVSS v4.0
8.5 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00595 · 47.8th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2026-03-06T20:26Z
EPSS history
Timeline
  • 06 MAR 20:26Z
    Parse Server: Endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user
    cvelistv5