# CVE-2026-104036: Sssd: sssd: denial of service via out-of-bounds write in nfs idmap plugin

> A local attacker can cause a denial of service or potential code execution in SSSD's NFS idmap plugin via an out-of-bounds write during identity lookups.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/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:** 6 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-104036, GHSA-95ww-m774-j7x2, OESA-2026-4425, UBUNTU-CVE-2026-104036

## What is CVE-2026-104036?

CVE-2026-104036 is a medium-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 6 Oct 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 SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-104036?


## How do I fix CVE-2026-104036?

Apply the vendor's patch.

## Is CVE-2026-104036 being exploited?

There is no known exploitation of CVE-2026-104036 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104036 and fix it if it is affected.

What it is: CVE-2026-104036 is a medium-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 6 Oct 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-2026-104036 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-2026-104036/ (Markdown: https://insights.sbomify.com/CVE-2026-104036/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104036
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104036
- OSV: https://osv.dev/vulnerability/CVE-2026-104036

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104036/
Summaries are generated and may contain mistakes; the official description above is the record.