Vulnerability in Parse-Community Parse-Server
CVE-2026-123487
Parse Server before 8.6.115 and 9.0.0 before 9.10.7-alpha.1 validates user email address format with a regular expression whose run time grows quadratically with input length and that is applied without a length limit. An unauthenticated attacker who knows the application ID can send a sign-up request, or a logged-in user can update their own email, with a long crafted email address to block the Node.js event loop and deny service to all clients.
Vulnerability class: ReDoS (Regular Expression Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-9492-427f-466x) (vendor-advisory)
- VulnCheck Advisory: Parse Server 9.0.0 before 9.10.7-alpha.1 ReDoS via Email Validation Regex (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123487?
- CVE-2026-123487 is a high-severity vulnerability in Parse-Community Parse-Server, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2026-11-06.
- How severe is CVE-2026-123487?
- High severity. CVSS v3 base score is 7.5 out of 10.