7.5 High

graphql-scalars PhoneNumber scalar is vulnerable to regular expression denial of service

CVE-2026-115887

Summary The regular expression behind GraphQLPhoneNumber since 1.24.1 backtracks exponentially. A string made of a run of digits followed by one character that makes the match fail (for example "1".repeat(30) + "x") blocks the JavaScript thread for seconds, and every additional digit doubles the time. graphql-js calls parseLiteral while validating a document and parseValue while coercing variables, so the regex runs for every request that merely contains such a value in a PhoneNumber position, before execution and before any authentication or authorization step of the server. One small unauthenticated request is enough to stall a server process. Affected versions graphql-scalars >= 1.24.1, <= 2.0.0 (2.0.0 is the current latest; the default branch still has the same pattern). Not affected: 1.24.0 and the earlier versions I checked (1.22.4, 1.23.0), which use the linear /^\+[1-9]\d{6,14}$/. Introduced by #2719 (c7f58da16, "PhoneNumber scalar is not fully compatible with E.164 format so updated regex to support phone number with extension"), released as 1.24.1 on 2025-01-29. The payload was ran against 1.22.4, 1.23.0, 1.24.0, 1.24.1, 1.24.2, 1.25.0, 1.26.0 and 2.0.0: the first three…

Assessment

CVSS: 7.5 (v3.1)
Severity: High
EPSS: 0.00487% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 October 2026
Last updated: 30 October 2026
Affected: npm · graphql-scalars
Weakness: CWE-1333

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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