GraphQL-core processes GraphQL queries from unauthenticated clients. The parser ignores comment tokens when enforcing the configured maximum token count, yet still allocates memory for each comment token. By inserting a heavily comment‑padded document that stays under the visible token threshold, an attacker can cause the parser to consume large amounts of memory before the downstream depth or complexity checks limit the request. The result is a denial of service through worker memory exhaustion. The weakness is identified by CWE‑400 (Unrestricted Input) and CWE‑770 (Memory Allocation).

The Python library graphql-core, versions 3.2.3 through 3.2.11 and any 3.3.0rc release prior to 3.3.0rc1, is affected. Versions 3.2.12 and 3.3.0rc1 and later contain the fix.

The CVSS score of 7.5 classifies this as a high severity vulnerability. No EPSS score is available, but the lack of authentication and the ability to send arbitrary GraphQL text make exploitation straightforward for any service that accepts GraphQL queries. The vulnerability is not listed in CISA KEV, yet it can be abused by remote attackers to exhaust available memory and disrupt service availability.