What is CVE-2026-35577?

CVE-2026-35577 is a medium-severity vulnerability in Apollographql Apollo-mcp-server, classified under Origin Validation Error. CVSS score: 6.8/10. Published 2026-04-09.

How severe is CVE-2026-35577?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Vulnerability in Apollographql Apollo-mcp-server

CVE-2026-35577

Apollo MCP Server is a Model Context Protocol server that exposes GraphQL operations as MCP tools. Prior to version 1.7.0, the Apollo MCP Server did not validate the Host header on incoming HTTP requests when using StreamableHTTP transport…

EPSS: 0.000 (8.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N.

Affected products

Apollographql Apollo-mcp-server — versions < 1.7.0

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

https://github.com/apollographql/apollo-mcp-server/security/advisories/GHSA-wqrj-vp8w-f8vh (x_refsource_CONFIRM)
https://github.com/apollographql/apollo-mcp-server/pull/602 (x_refsource_MISC)
https://github.com/apollographql/apollo-mcp-server/pull/635 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-35577?: CVE-2026-35577 is a medium-severity vulnerability in Apollographql Apollo-mcp-server, classified under Origin Validation Error. CVSS score: 6.8/10. Published 2026-04-09.
How severe is CVE-2026-35577?: Medium severity. CVSS v3 base score is 6.8 out of 10.