# CVE-2026-90996: Sssd: sssd: denial of service in nss responder via crafted zero-length requests

> A local unprivileged user can cause a denial of service in the SSSD NSS responder by sending crafted zero-length requests.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **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:** 14 Sep 2026
- **Updated:** 7 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-90996, GHSA-xg93-wm7f-rmcx, UBUNTU-CVE-2026-90996

## What is CVE-2026-90996?

CVE-2026-90996 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 14 Sep 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. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-90996?

It affects 3 products.


Products: Fedoraproject Sssd, Redhat Enterprise Linux, Redhat Openshift Container Platform.

## How do I fix CVE-2026-90996?

Apply the vendor's patch.

## Is CVE-2026-90996 being exploited?

There is no known exploitation of CVE-2026-90996 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2022-4254](https://insights.sbomify.com/CVE-2022-4254/): Other in SSSD (high 8.8)
- [CVE-2012-3462](https://insights.sbomify.com/CVE-2012-3462/): Auth bypass in sssd (high 8.8)
- [CVE-2026-104048](https://insights.sbomify.com/CVE-2026-104048/): Sssd: sssd: authorization bypass via cross-domain username collision in hbac evaluation (medium 6.8)
- [CVE-2015-5292](https://insights.sbomify.com/CVE-2015-5292/): Denial of service in n/a (medium 6.8)
- [CVE-2026-12610](https://insights.sbomify.com/CVE-2026-12610/): Sssd: use-after-free crash in sssd' 'sssd_pam' process (medium 6.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90996 and fix it if it is affected.

What it is: CVE-2026-90996 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 14 Sep 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-2026-90996 in the wild and no public exploit code.

Affected product: Redhat Enterprise Linux. 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-2026-90996/ (Markdown: https://insights.sbomify.com/CVE-2026-90996/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90996
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90996
- OSV: https://osv.dev/vulnerability/CVE-2026-90996

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90996/
Summaries are generated and may contain mistakes; the official description above is the record.