CVE-2026-100631

HIGH
Published Sep 26, 2026 Modified Sep 30, 2026 CWE-943

Description

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.

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CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0036
Probability of exploitation
0.27%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-943 CWE-943

References

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-100631? +
CVE-2026-100631 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0036, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-100631? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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