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

> Stored XSS in RustFS Console allows attackers to steal admin credentials and take over accounts via malicious PDF previews.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Feb 2026
- **Updated:** 25 Feb 2026
- **Also known as:** GHSA-v9fg-3cr2-277j

## 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 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-27822?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rustfs` | crates.io | All versions | 1.0.0-alpha.83 |
| `rustfs` | crates.io | All versions | 1.0.0-alpha.83 |

Products: Rustfs Rustfs.

## How do I fix CVE-2026-27822?

Upgrade rustfs to 1.0.0-alpha.83 or later.

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

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27822 and fix it if it is affected.

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

Affected packages and fixed versions:
- rustfs (crates.io): affected all versions; fixed in 1.0.0-alpha.83
- rustfs (crates.io): affected all versions; fixed in 1.0.0-alpha.83

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-27822/ (Markdown: https://insights.sbomify.com/CVE-2026-27822/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27822
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27822
- OSV: https://osv.dev/vulnerability/CVE-2026-27822

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27822/
Summaries are generated and may contain mistakes; the official description above is the record.