# CVE-2026-34003: Xorg: xwayland: x.org x server: information exposure and denial of service via out-of-bounds memory access

> A local attacker can trigger out-of-bounds memory access in the X.Org X server, leading to information disclosure or denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Apr 2026
- **Updated:** 15 Jul 2026
- **Also known as:** AZL-84633, AZL-84845, BELL-CVE-2026-34003, DEBIAN-CVE-2026-34003, ECHO-d72b-8ceb-b726, GHSA-5mqr-3465-c7p6, UBUNTU-CVE-2026-34003

## What is CVE-2026-34003?

CVE-2026-34003 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 23 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-34003?


## How do I fix CVE-2026-34003?

Apply the vendor's patch.

## Is CVE-2026-34003 being exploited?

There is no known exploitation of CVE-2026-34003 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34003 and fix it if it is affected.

What it is: CVE-2026-34003 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 23 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34003 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2026-34003/ (Markdown: https://insights.sbomify.com/CVE-2026-34003/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34003
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34003
- OSV: https://osv.dev/vulnerability/CVE-2026-34003

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34003/
Summaries are generated and may contain mistakes; the official description above is the record.