# CVE-2026-18938: Integer overflow in Red Hat Enterprise Linux 10

> A local attacker can cause a denial of service in p11-kit via an integer overflow leading to heap corruption on 32-bit systems.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Aug 2026
- **Updated:** 7 Aug 2026
- **Also known as:** AZL-95481, DEBIAN-CVE-2026-18938, ECHO-09a0-891c-526d, GHSA-6x8p-h5fj-5ppr, OESA-2026-3503, ROOT-OS-DEBIAN-11-CVE-2026-18938, ROOT-OS-DEBIAN-12-CVE-2026-18938, ROOT-OS-DEBIAN-13-CVE-2026-18938, UBUNTU-CVE-2026-18938

## What is CVE-2026-18938?

CVE-2026-18938 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 7 Aug 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 p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a memory corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-18938?


## How do I fix CVE-2026-18938?

Apply the vendor's patch.

## Is CVE-2026-18938 being exploited?

There is no known exploitation of CVE-2026-18938 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18938 and fix it if it is affected.

What it is: CVE-2026-18938 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 7 Aug 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-2026-18938 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-2026-18938/ (Markdown: https://insights.sbomify.com/CVE-2026-18938/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18938
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18938
- OSV: https://osv.dev/vulnerability/CVE-2026-18938

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18938/
Summaries are generated and may contain mistakes; the official description above is the record.