CVE Vulnerabilities

CVE-2026-23897

Inefficient Regular Expression Complexity

Published: Feb 04, 2026 | Modified: Mar 18, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
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Apollo Server is an open-source, spec-compliant GraphQL server thats compatible with any GraphQL client, including Apollo Client. In versions from 2.0.0 to 3.13.0, 4.2.0 to before 4.13.0, and 5.0.0 to before 5.4.0, the default configuration of startStandaloneServer from @apollo/server/standalone is vulnerable to denial of service (DoS) attacks through specially crafted request bodies with exotic character set encodings. This issue does not affect users that use @apollo/server as a dependency for integration packages, like @as-integrations/express5 or @as-integrations/next, only direct usage of startStandaloneServer.

Weakness

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

Affected Software

NameVendorStart VersionEnd Version
Apollo_serverApollographql2.0.0 (including)3.13.0 (including)
Apollo_serverApollographql4.2.0 (including)4.13.0 (excluding)
Apollo_serverApollographql5.0.0 (including)5.4.0 (excluding)

Potential Mitigations

References