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GHSA-vc89-5g3r-cmhh

HighCVSS 8.6 / 10

Published Mar 5, 2026·Last modified Mar 16, 2026

Affected Components(0)

No affected components available

Description

Impact

Parse Server's readOnlyMasterKey option allows access with master-level read privileges but is documented to deny all write operations. However, some endpoints incorrectly accept the readOnlyMasterKey for mutating operations. This allows a caller who only holds the readOnlyMasterKey to create, modify, and delete Cloud Hooks and to start Cloud Jobs, which can be used for data exfiltration.

Any Parse Server deployment that uses the readOnlyMasterKey option is affected. Note than an attacker needs to know the readOnlyMasterKey to exploit this vulnerability.

Patches

The fix adds authorization checks, rejecting mutating requests made with the readOnlyMasterKey.

Workarounds

There is no known workaround other than upgrading. If upgrading is not immediately possible, ensure the readOnlyMasterKey value is not shared with untrusted parties.

Resources

GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-vc89-5g3r-cmhh
Fixed in Parse Server 9.4.1-alpha.3: https://github.com/parse-community/parse-server/releases/tag/9.4.1-alpha.3
Fixed in Parse Server 8.6.4: https://github.com/parse-community/parse-server/releases/tag/8.6.4

Risk Scores

Base Score

8.6

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs high-level or administrative privileges. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence

6.1

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS

0.38%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit

Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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High severity

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