Vulnerability in Parse-Community Parse-Server

CVE-2026-100631

Parse Server is an open source backend server. In versions prior to 8.6.90 and in versions from 9.0.0 prior to 9.10.1-alpha.9, the device token deduplication logic for installation records does not validate the type of client-supplied installation fields before using them to build database queries. An unauthenticated remote attacker who knows only the public application ID can submit non-string values in these fields to inject query operators, causing the deduplication cleanup — which runs with elevated privileges before class-level permissions are evaluated — to delete every device registration in the application or an attacker-chosen subset of them. No account, session token, master key, or user interaction is required. Deleted registrations cannot be recovered on the server, so push notifications cannot be delivered until every client re-registers. Any deployment that exposes the REST API to clients and uses push notifications is affected in its default configuration. Versions 8.6.90 and 9.10.1-alpha.9 fix the issue by rejecting non-string values with a client error and by scoping the deduplication cleanup to the calling application. No workaround other than upgrading is available.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.7% 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-2026-100631: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-100631?
CVE-2026-100631 is a high-severity vulnerability in Parse-Community Parse-Server, classified under Improper Neutralization of Special Elements in Data Query Logic. CVSS score: 7.5/10. Published 2026-09-26.
How severe is CVE-2026-100631?
High severity. CVSS v3 base score is 7.5 out of 10.