Rust has Critical Stored XSS in Preview Modal, leading to Administrative Account Takeover

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-27822: 5.05% estimated exploitation activity in the next 30 days; percentile 92.32 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A Stored Cross-Site Scripting (XSS) vulnerability in the RustFS Console allows an attacker to execute arbitrary JavaScript in the context of the management console. By bypassing the PDF preview logic, an attacker can steal administrator credentials from localStorage, leading to full account takeover and system compromise. Details The vulnerability exists due to improper validation of the response content type during the file preview process and a lack of origin separation between the S3 object delivery and the management console. 1. Origin of Credentials: The RustFS Console stores highly sensitive S3 credentials (AccessKey, SecretKey, SessionToken) in the browser's localStorage. - File: console/composables/useAuth.ts - Evidence: Lines 14 and 18-25 show that credentials are held in useLocalStorage('auth.credentials', {}) and useLocalStorage('auth.permanent', undefined). 2. Insecure Preview Implementation: In console/components/object/preview-modal.vue, the application…

Published by the source

25 Feb 2026, 23:00 UTC

Last modified by the source

25 Feb 2026, 23:00 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v9fg-3cr2-277j

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# Patch Next advisory brief: CVE-2026-27822

Advisory: Rust has Critical Stored XSS in Preview Modal, leading to Administrative Account Takeover
IDs: CVE-2026-27822, GHSA-v9fg-3cr2-277j
Record: https://patchnext.com/advisories/cve-2026-27822 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: rustfs 1.0.0-alpha.83. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io rustfs: affected < 1.0.0-alpha.83; fixed in 1.0.0-alpha.83

## Suggested inspection (read-only)
- crates.io rustfs: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on rustfs.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v9fg-3cr2-277j (GitHub-reviewed advisory GHSA-v9fg-3cr2-277j lists affected ranges: crates.io rustfs >=0 <1.0.0-alpha.83)

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