GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit
GraphQL-core is a Python port of the GraphQL.js reference implementation. From 3.2.3 until 3.2.12 and 3.3.0rc1, the parser's max_tokens limit in Parser.advance_lexer counts only non-comment tokens returned after Lexer.lookahead skips comments. Each skipped comment is still allocated as a Token and retained through token.next and token.prev, allowing a highly compressible comment-padded GraphQL document to pass a low token limit while consuming memory. An unauthenticated remote attacker can exhaust worker memory before AST-based depth or complexity controls run. This issue is fixed in versions 3.2.12 and 3.3.0rc1.
CVE-2026-75508
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-75508
graphql-core
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "graphql-python",
"product": "graphql-core",
"versions": [
{
"status": "affected",
"version": ">= 3.2.3, < 3.2.12"
},
{
"status": "affected",
"version": ">= 3.3.0a3, < 3.3.0rc1"
}
]
}
]- Related CVEs
- CVE-2026-75508
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #50393 · Revision 1
- Added to Heist Feed
- Publisher date