Vulnerability in Parse-Community Parse-Server

CVE-2026-34595

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.70 and 9.7.0-alpha.18, an authenticated user with find class-level permission can bypass the protectedFields class-level permission setting on LiveQuery subscriptions. By sending a subscription with a $or, $and, or $nor operator value as a plain object with numeric keys and a length property (an "array-like" object) instead of an array, the protected-field guard is bypassed. The subscription event firing acts as a binary oracle, allowing the attacker to infer whether a protected field matches a given test value. This issue has been patched in versions 8.6.70 and 9.7.0-alpha.18.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-34595: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34595?
CVE-2026-34595 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 4.3/10. Published 2026-03-31.
How severe is CVE-2026-34595?
Medium severity. CVSS v3 base score is 4.3 out of 10.