Is there a public exploit for CVE-2026-112949?

No public exploit for CVE-2026-112949 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-112949?

CVE-2026-112949 scores CVSS 4.7 (v3.1), rated medium. EPSS puts the chance of exploitation in the next 30 days at 0.34%.

What does CVE-2026-112949 affect?

CVE-2026-112949 affects @vitest, vitest-dev @vitest/mocker.

4.7 Medium

Vitest is a Vite-native testing framework for JavaScript and TypeScript projects.

CVE-2026-112949

Summary @vitest/mocker's interceptorPlugin accepts mock registrations on Vite's dev-server WebSocket with no authentication, and interpolates the mock's url into generated module source without escaping. A client that can reach the dev server can make it serve arbitrary JavaScript in place of any project module, which then runs in the developer's browser on the dev-server origin. Same handler and same unauthenticated caller as GHSA-82fw-gwwq-j7x9; that fix (8ff9b9a9efca7c6cfd5243569440de8d7a33aec4, PR #10972) hardened only the redirect branch and left the manual branch reaching the unescaped generator. Patches Fixed in @vitest/mocker 5.0.3, released on 2026-09-30 (PR #11377), and backported to 4.1.12. createManualModuleSource now serializes the module URL and the export names with JSON.stringify, so a registered mock cannot change the generated code. Projects that call mockerPlugin() or interceptorPlugin() directly need @vitest/mocker 4.1.12 or 5.0.3. Details packages/mocker/src/utils.ts:6-9 builds module source by string interpolation: ts export function createManualModuleSource(moduleUrl: string, exports: string[], globalAccessor = '"vitestmocker"'): string { const source =…

Assessment

CVSS: 4.7 (v3.1)
Severity: Medium
EPSS: 0.34% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 20 October 2026
Last updated: 23 October 2026
Affected: @vitest · vitest-dev · mocker · vitest · @vitest/mocker
Weakness: CWE-116, CWE-306, CWE-94
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

At the source

References

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