High severity · published Oct 22, 2026
CVE-2026-75508
GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit
New
7.5
CVSS
0.6%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GR
graphql-core · graphql-python
>= 3.2.3, < 3.2.12; >= 3.3.0a3, < 3.3.0rc1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-75508
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-75508
github.com
https://github.com/graphql-python/graphql-core/commit/437dea102e92fdf05a2971ca76787c5a5bad875a
github.com
https://github.com/graphql-python/graphql-core/commit/80ef435a1808fbbcc4aaac63ae76771a1c91002d
github.com
https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12
github.com
https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1
github.com
https://github.com/graphql-python/graphql-core/security/advisories/GHSA-r77w-qph3-7vf8
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