# CVE-2026-94422: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape

> Attackers can bypass D-Bus message filtering in xdg-dbus-proxy to escape Flatpak sandboxes and execute arbitrary code.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 2 Oct 2026
- **Updated:** 24 Oct 2026
- **Also known as:** ALSA-2026:90522, ALSA-2026:90523, AZL-105923, DEBIAN-CVE-2026-94422, ECHO-ab97-ca4d-bc8e, GHSA-2cgv-pwcq-wvpq, MGASA-2026-0480, OESA-2026-4640, OESA-2026-4641, OESA-2026-4642, OESA-2026-4643, RLSA-2026:90522, RLSA-2026:90523, UBUNTU-CVE-2026-94422

## What is CVE-2026-94422?

CVE-2026-94422 is a high-severity vulnerability in Fedora, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox. xdg-dbus-proxy was designed to be part of the sandbox boundary for Flatpak, but it is released as a separate project and is sometimes used by other app frameworks such as Firejail.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-94422?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `xdg-dbus-proxy` | AlmaLinux:10 | All versions | 0.1.5-4.el10_2.1 |
| `xdg-dbus-proxy` | AlmaLinux:9 | All versions | 0.1.3-1.el9_8.1 |
| `xdg-dbus-proxy` | Rocky Linux:10 | All versions | 0:0.1.5-4.el10_2.1 |
| `xdg-dbus-proxy` | Rocky Linux:9 | All versions | 0:0.1.3-1.el9_8.1 |

## How do I fix CVE-2026-94422?

Upgrade to a fixed version.

## Is CVE-2026-94422 being exploited?

There is no known exploitation of CVE-2026-94422 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-94422 and fix it if it is affected.

What it is: CVE-2026-94422 is a high-severity vulnerability in Fedora, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-94422 in the wild and no public exploit code.

Affected product: Fedora. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-94422/ (Markdown: https://insights.sbomify.com/CVE-2026-94422/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-94422
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-94422
- OSV: https://osv.dev/vulnerability/CVE-2026-94422

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-94422/
Summaries are generated and may contain mistakes; the official description above is the record.