CVE-2026-27822 Rust has Critical Stored XSS in Preview Modal, leading to Administrative Account Takeover

What is CVE-2026-27822?

CVE-2026-27822 is a critical cross-site scripting vulnerability in rustfs, published on 25 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

RustFS is a distributed object storage system built in Rust. Prior to version 1.0.0-alpha.83, 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. Version 1.0.0-alpha.83 fixes the issue.

Weakness: CWE-79

Which versions are affected by CVE-2026-27822?

2 open source packages ship an affected version, including rustfs. It affects 1 product.

Products include Rustfs Rustfs.

How do I fix CVE-2026-27822?

Upgrade rustfs to 1.0.0-alpha.83 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-27822 being exploited?

There is no known exploitation of CVE-2026-27822 in the wild and no public exploit code.

Other vulnerabilities in rustfs

• CVE-2025-68926 RustFS has a gRPC Hardcoded Token Authentication Bypass Critical 9.8
• CVE-2025-68705 RustFS Path Traversal Vulnerability High 8.8
• CVE-2026-40937 RustFS: Missing admin authorization on notification target endpoints allows unauthenticated configuration of event webhooks High 8.3
• CVE-2026-27607 RustFS's Missing Post Policy Validation leads to Arbitrary Object Write High 8.1
• CVE-2026-21862 RustFS sourceIp bypass via spoofed X-Forwarded-For/Real-IP headers High 7.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-v9fg-3cr2-277j.