SB2026052315 - Inefficient regular expression complexity in parse-server

Description

This security bulletin contains information about 1 vulnerability.

1) Inefficient regular expression complexity (CVE-ID: CVE-2026-47138)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in the request-header parser when processing the client SDK version field on /parse/* requests. A remote attacker can send a single specially crafted HTTP request to cause a denial of service.

The issue is reachable before session authentication and before rate limiting, and the X-Parse-Client-Version header or _ClientVersion JSON body field can trigger prolonged synchronous CPU consumption on a Node.js worker. Production deployments running the default configuration are affected.

Remediation

Install update from vendor's website.

References

• https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm
• https://github.com/parse-community/parse-server/pull/10463