# CVE-2026-68743: Sssd: sssd: pam responder out-of-bounds read via unchecked auth_token_length in protocol v1

> A local attacker can cause a denial of service in SSSD by sending a crafted request to the PAM responder, triggering an out-of-bounds read and crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 4 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** CLSA-2026-1787314091, CLSA-2026-1787394253, CLSA-2026-1787394686, CLSA-2026-1788440142, CLSA-2026-1789478531, CLSA-2026-1789479226, DEBIAN-CVE-2026-68743, GHSA-3v6f-w66g-3mv6, OESA-2026-3574, SUSE-SU-2026:3797-1, SUSE-SU-2026:4027-1, UBUNTU-CVE-2026-68743, USN-8718-1

## What is CVE-2026-68743?

CVE-2026-68743 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 4 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 SSSD. The extract_authtok_v1() function in the PAM responder does not validate the auth_token_length field against the remaining buffer size before processing. A local attacker can exploit this via a crafted protocol v1 request to the PAM responder socket, causing an out-of-bounds read and process crash, resulting in a denial of service.

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

## Which versions are affected by CVE-2026-68743?

It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `sssd` | SUSE:Linux Enterprise Micro 5.3 | All versions | 2.5.2-150400.4.51.1 |
| `sssd` | SUSE:Linux Enterprise Micro 5.4 | All versions | 2.5.2-150400.4.51.1 |
| `sssd` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 1.16.1-7.79.1 |

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

## How do I fix CVE-2026-68743?

Apply the vendor's patch.

## Is CVE-2026-68743 being exploited?

There is no known exploitation of CVE-2026-68743 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-2026-68743 and fix it if it is affected.

What it is: CVE-2026-68743 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 4 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-2026-68743 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-2026-68743/ (Markdown: https://insights.sbomify.com/CVE-2026-68743/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68743
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68743
- OSV: https://osv.dev/vulnerability/CVE-2026-68743

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68743/
Summaries are generated and may contain mistakes; the official description above is the record.