CVE-2026-75508: GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit
The parser’s max_tokens limit — the documented defence against oversized GraphQL
documents — did not count comment tokens. A document padded with comments could
therefore pass a max_tokens check of any size while still allocating one Token
object per comment, all of which stay reachable for the lifetime of the parsed
document. A 38 MB comment-padded payload allocated roughly 92 MB of additional
resident memory with max_tokens=5 in force.
References
- github.com/advisories/GHSA-r77w-qph3-7vf8
- github.com/graphql-python/graphql-core/commit/437dea102e92fdf05a2971ca76787c5a5bad875a
- github.com/graphql-python/graphql-core/commit/80ef435a1808fbbcc4aaac63ae76771a1c91002d
- github.com/graphql-python/graphql-core/releases/tag/v3.2.12
- github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1
- github.com/graphql-python/graphql-core/security/advisories/GHSA-r77w-qph3-7vf8
- nvd.nist.gov/vuln/detail/CVE-2026-75508
Code Behaviors & Features
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