Vulnerability · Published Feb 4, 2026 · Assigned by GitHub_M
CVE-2026-23897Apollo Server is vulnerable to denial of service with `startStandaloneServer`
High 7.5
In plain English
A high-severity regular-expression denial of service in apollo-server from apollographql. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Apollo Server is an open-source, spec-compliant GraphQL server that's 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @apollo/server | 4.13.0 | GHSA-mp6q-xf9x-fwf7 |
| npm | @apollo/server | 5.4.0 | GHSA-mp6q-xf9x-fwf7 |
| npm | apollo-server | no fix listed | GHSA-mp6q-xf9x-fwf7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| apollographql | apollo-server | >= 2.0.0, <= 3.13.0>= 4.2.0, < 4.13.0>= 5.0.0, < 5.4.0 |
Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/apollographql/apollo-server/security/advisories/GHSA-mp6q-xf9x-fwf7 x_refsource_CONFIRM
- https://github.com/apollographql/apollo-server/commit/d25a5bdc377826ad424fcf7f8d1d062055911643 x_refsource_MISC
- https://github.com/apollographql/apollo-server/commit/e9d49d163a86b8a33be56ed27c494b9acd5400a4 x_refsource_MISC