CVE-2026-39321
Parse Server has a login timing side-channel reveals user existence
Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.8.0-alpha.6 and 8.6.74, he login endpoint response time differs measurably depending on whether the submitted username or email exists in the database. When a user is not found, the server responds immediately. When a user exists but the password is wrong, a bcrypt comparison runs first, adding significant latency. This timing difference allows an unauthenticated attacker to enumerate valid usernames. This vulnerability is fixed in 9.8.0-alpha.6 and 8.6.74.
INFO
Published Date :
April 7, 2026, 6:16 p.m.
Last Modified :
April 15, 2026, 5:20 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Parse Server to a fixed version.
- Apply security patches promptly.
- Monitor for unauthorized access.
- Review user account security.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-39321.
| URL | Resource |
|---|---|
| https://github.com/parse-community/parse-server/pull/10398 | Issue Tracking Patch |
| https://github.com/parse-community/parse-server/pull/10399 | Issue Tracking Patch |
| https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2v | Mitigation Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-39321 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-39321
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-39321 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-39321 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 15, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* versions from (including) 9.0.0 up to (excluding) 9.8.0 *cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha1:*:*:*:node.js:*:* *cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha2:*:*:*:node.js:*:* *cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha3:*:*:*:node.js:*:* *cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha4:*:*:*:node.js:*:* *cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha5:*:*:*:node.js:*:* *cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* versions up to (excluding) 8.6.74 Added Reference Type GitHub, Inc.: https://github.com/parse-community/parse-server/pull/10398 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/parse-community/parse-server/pull/10399 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2v Types: Mitigation, Patch, Vendor Advisory -
New CVE Received by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Description Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.8.0-alpha.6 and 8.6.74, he login endpoint response time differs measurably depending on whether the submitted username or email exists in the database. When a user is not found, the server responds immediately. When a user exists but the password is wrong, a bcrypt comparison runs first, adding significant latency. This timing difference allows an unauthenticated attacker to enumerate valid usernames. This vulnerability is fixed in 9.8.0-alpha.6 and 8.6.74. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-208 Added Reference https://github.com/parse-community/parse-server/pull/10398 Added Reference https://github.com/parse-community/parse-server/pull/10399 Added Reference https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2v