Vulnerability · Published Mar 6, 2026 · Assigned by GitHub_M

CVE-2026-30229Parse Server: Endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user

High 8.5

In plain English

A high-severity incorrect authorization in parse-server from parse-community. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.5High

Exploit odds (30 days)0.4%top 62.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.6 and 9.5.0-alpha.4, the readOnlyMasterKey can call POST /loginAs to obtain a valid session token for any user. This allows a read-only credential to impersonate arbitrary users with full read and write access to their data. Any Parse Server deployment that uses readOnlyMasterKey is affected. This issue has been patched in versions 8.6.6 and 9.5.0-alpha.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	parse-server	8.6.6	GHSA-79wj-8rqv-jvp5
npm	parse-server	9.5.0-alpha.4	GHSA-79wj-8rqv-jvp5

Affected products (as reported)

Vendor	Product	Versions
parse-community	parse-server	< 8.6.6< 9.5.0-alpha.4

Weakness: CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

References

https://github.com/parse-community/parse-server/security/advisories/GHSA-79wj-8rqv-jvp5 x_refsource_CONFIRM
https://github.com/parse-community/parse-server/releases/tag/8.6.6 x_refsource_MISC
https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.4 x_refsource_MISC