CVE-2026-34574

EPSS 0.03%

Parse Server has a session field immutability bypass via falsy-value guard

Published: 4/1/2026Modified: 4/6/2026

Description

### Impact An authenticated user can bypass the immutability guard on session fields (`expiresAt`, `createdWith`) by sending a null value in a PUT request to the session update endpoint. This allows nullifying the session expiry, making the session valid indefinitely and bypassing configured session length policies. ### Patches The truthiness-based guard checks were replaced with key-presence checks that reject any value for protected session fields, including null. ### Workarounds There is no known workaround. A `beforeSave` trigger on `_Session` could be used to reject null values for `expiresAt` and `createdWith`.

Affected packages (2)

CVSS scores

SourceVersionSeverityVector
osvCVSS 4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

References (7)