# CVE-2019-19338: Information disclosure in Linux Kernel

> Guests on affected Intel Cascade Lake CPUs with TSX enabled may leak sensitive data due to improper buffer clearing during speculative execution errors.

- **Severity:** Medium 5.5 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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:** 13 Jul 2020
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-qv7j-3q84-2q98, UBUNTU-CVE-2019-19338

## What is CVE-2019-19338?

CVE-2019-19338 is a medium-severity vulnerability in Linux kernel, published on 13 Jul 2020. 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 fix for CVE-2019-11135, in the Linux upstream kernel versions before 5.5 where, the way Intel CPUs handle speculative execution of instructions when a TSX Asynchronous Abort (TAA) error occurs. When a guest is running on a host CPU affected by the TAA flaw (TAA_NO=0), but is not affected by the MDS issue (MDS_NO=1), the guest was to clear the affected buffers by using a VERW instruction mechanism. But when the MDS_NO=1 bit was exported to the guests, the guests did not use the VERW mechanism to clear the affected buffers. This issue affects guests running on Cascade Lake CPUs and requires that host has 'TSX' enabled. Confidentiality of data is the highest threat associated with this vulnerability.

Weakness: CWE-385 (Covert Timing Channel), CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2019-19338?

It affects 2 products.


Products: Linux kernel, Redhat Enterprise Linux.

## How do I fix CVE-2019-19338?

Apply the vendor's patch.

## Is CVE-2019-19338 being exploited?

There is no known exploitation of CVE-2019-19338 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-19338 and fix it if it is affected.

What it is: CVE-2019-19338 is a medium-severity vulnerability in Linux kernel, published on 13 Jul 2020. 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-2019-19338 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2019-19338/ (Markdown: https://insights.sbomify.com/CVE-2019-19338/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-19338
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-19338
- OSV: https://osv.dev/vulnerability/CVE-2019-19338

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-19338/
Summaries are generated and may contain mistakes; the official description above is the record.