CVE-2026-31901: Parse server Parse Server Vulnerable To User Vulnerability
MODERATECVE-2026-31901 is a MODERATE parse server vulnerable to user vulnerability (CWE-204: Observable Response Discrepancy) affecting Parse server libraries in the npm ecosystem. The issue involves parse server vulnerable to user enumeration via email verification endpoint. Remediation is available by upgrading affected packages to version 9.6.0-alpha.8, 8.6.34.
CVE-2026-31901 at a Glance
How to Fix CVE-2026-31901
To remediate this vulnerability, upgrade all affected Parse server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install parse-server@9.6.0-alpha.8npm install parse-server@8.6.34Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls parse-serverHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-31901, inspect your project dependencies using npm:
npm ls parse-serverAnalyze the terminal output to locate any version of Parse server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 9.6.0-alpha.8), your application is affected.
Note: The npm ls parse-server command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-204: Observable Response Discrepancy, where the product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere. In Parse server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-31901 Affected Parse server Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
parse-server
|
npm |
≥ 9.0.0-alpha.1
< 9.6.0-alpha.8
|
9.6.0-alpha.8
|
|
parse-server
|
npm |
< 8.6.34
|
8.6.34
|
References
Frequently Asked Questions
What is CVE-2026-31901?
Which Parse server versions are affected?
What version fixes CVE-2026-31901?
Is parse-server affected?
What CWE is associated with CVE-2026-31901?
How can I check npm dependencies for CVE-2026-31901?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-w54v-hf9p-8856",
"modified" : "2026-03-11T21:37:44Z",
"published" : "2026-03-11T00:36:13Z",
"aliases" : [ "CVE-2026-31901" ],
"summary" : "Parse Server vulnerable to user enumeration via email verification endpoint",
"details" : "### Impact\n\nThe email verification endpoint (`/verificationEmailRequest`) returns distinct error responses depending on whether an email address belongs to an existing user, is already verified, or does not exist. An attacker can send requests with different email addresses and observe the error codes to determine which email addresses are registered in the application.\n\nThis is a user enumeration vulnerability that affects any Parse Server deployment with email verification enabled (`verifyUserEmails: true`).\n\n### Patches\n\nThe fix introduces a new Parse Server option `emailVerifySuccessOnInvalidEmail` (default: `true`) that returns a generic success response for all verification email requests, regardless of whether the email address is valid, already verified, or non-existent. This prevents an attacker from distinguishing between these cases.\n\nThe fix also strengthens the input validation for the related `resetPasswordSuccessOnInvalidEmail` option, and adds security checks that warn when either enumeration mitigation is disabled.\n\n### Workarounds\n\nThere is no known workaround.\n\n### References\n\n- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-w54v-hf9p-8856\n- Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.8\n- Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.34",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "parse-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "9.0.0-alpha.1"
}, {
"fixed" : "9.6.0-alpha.8"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "parse-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "8.6.34"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-w54v-hf9p-8856"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-31901"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/parse-community/parse-server"
}, {
"type" : "WEB",
"url" : "https://github.com/parse-community/parse-server/releases/tag/8.6.34"
}, {
"type" : "WEB",
"url" : "https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.8"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-204" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-11T00:36:13Z",
"nvd_published_at" : "2026-03-11T20:16:16Z"
}
}