@vitejs/plugin-rsc has Arbitrary File Read via `/__vite_rsc_findSourceMapURL` Endpoint on Development

published 2025-12-16 10 mo ago modified 2026-06-17 4 mo ago also GHSA-g239-q96q-x4qm , EUVD-2025-203834

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits: 0; none known

@vitejs/plugin-rs provides React Server Components (RSC) support for Vite. Prior to version 0.5.8, the `/__vite_rsc_findSourceMapURL` endpoint in `@vitejs/plugin-rsc` allows unauthenticated arbitrary file read during development mode. An attacker can read any file accessible to the Node.js process by sending a crafted HTTP request with a `file://` URL in the `filename` query parameter. Version 0.5.8 fixes the issue.

Patch / fix

fixed in 1 links 3

npm @vitejs/plugin-rsc 0.5.8

github.com/vitejs/vite-plugin-react@582fba0 commit
github.com/facebook/react#29708 pull request
github.com/facebook/react#30741 pull request

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 10 mo ago (2025-12-16)

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@vitejs/plugin-rsc	<0.5.8	0.5.8

Affected products

vitejs vite-plugin-react

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-73 External Control of File Name or Path

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary