What is CVE-2026-49857?

CVE-2026-49857 is a high-severity vulnerability in Ymw0407 Auth-fetch-mcp, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.4/10. Published 2026-08-13.

How severe is CVE-2026-49857?

High severity. CVSS v3 base score is 7.4 out of 10.

SSRF in Ymw0407 Auth-fetch-mcp

CVE-2026-49857

auth-fetch-mcp is an MCP server that lets AI assistants fetch content from authenticated web pages. Version 3.0.1 implements SSRF protection in `assertSafeUrl()` (`src/security.ts`) to block requests to private and loopback addresses. Howe…

Vulnerability class: SSRF (Server-Side Request Forgery)

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N.

Affected products

Ymw0407 Auth-fetch-mcp — versions < 3.0.2

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-49857?: CVE-2026-49857 is a high-severity vulnerability in Ymw0407 Auth-fetch-mcp, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.4/10. Published 2026-08-13.
How severe is CVE-2026-49857?: High severity. CVSS v3 base score is 7.4 out of 10.