# CVE-2026-3497: Null dereference in openssh

> Attackers can trigger undefined behavior via uninitialized memory access in GSSAPI key exchange, potentially leading to code execution or crashes.

- **Severity:** Low 2.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Mar 2026
- **Updated:** 15 Oct 2026
- **Also known as:** ALSA-2026:6461, ALSA-2026:6462, ALSA-2026:6463, CLSA-2026-1774366569, CLSA-2026-1774369958, CLSA-2026-1775220882, CLSA-2026-1775752680, CLSA-2026-1777455730, CLSA-2026-1777950533, DEBIAN-CVE-2026-3497, ECHO-09c4-31b3-a9b0, GHSA-wcpp-3x59-h8vp, RHSA-2026:10714, RHSA-2026:13750, RHSA-2026:14924, RHSA-2026:15891, RHSA-2026:15893, RHSA-2026:6461, RHSA-2026:6462, RHSA-2026:6463, RHSA-2026:7107, RHSA-2026:9415, RHSA-2026:9732, RLSA-2026:6461, RLSA-2026:6462, RLSA-2026:6463, UBUNTU-CVE-2026-3497

## What is CVE-2026-3497?

CVE-2026-3497 is a low-severity vulnerability in Canonical Ubuntu Linux, published on 12 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions. This vulnerability affects the GSSAPI patches added by various Linux distributions and does not affect the OpenSSH upstream project itself. The usage of sshpkt_disconnect() on an error, which does not terminate the process, allows an attacker to send an unexpected GSSAPI message type during the GSSAPI key exchange to the server, which will call the underlying function and continue the execution of the program without setting the related connection variables. As the variables are not initialized to NULL the code later accesses those uninitialized variables, accessing random memory, which could lead to undefined behavior. The recommended workaround is to use ssh_packet_disconnect() instead, which does terminate the process. The impact of the vulnerability depends heavily on the compiler flag hardening configuration.

Weakness: CWE-824 (Access of Uninitialized Pointer), CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2026-3497?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openssh` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh-askpass` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh-clients` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh-keycat` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh-keysign` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh-server` | AlmaLinux:10 | All versions | 9.9p1-13.el10_1.alma.1 |
| `openssh` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-askpass` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-cavs` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-clients` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-keycat` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-ldap` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `openssh-server` | AlmaLinux:8 | All versions | 8.0p1-28.el8_10 |
| `pam_ssh_agent_auth` | AlmaLinux:8 | All versions | 0.10.3-7.28.el8_10 |
| `openssh` | AlmaLinux:9 | All versions | 8.7p1-48.el9_7.alma.1 |
| `openssh-askpass` | AlmaLinux:9 | All versions | 8.7p1-48.el9_7.alma.1 |
| `openssh-clients` | AlmaLinux:9 | All versions | 8.7p1-48.el9_7.alma.1 |
| `openssh-keycat` | AlmaLinux:9 | All versions | 8.7p1-48.el9_7.alma.1 |
| `openssh-server` | AlmaLinux:9 | All versions | 8.7p1-48.el9_7.alma.1 |
| `pam_ssh_agent_auth` | AlmaLinux:9 | All versions | 0.10.4-5.48.el9_7.alma.1 |
| `openssh` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-askpass` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-askpass-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-clients` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-clients-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-debugsource` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-keycat` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-keycat-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-keysign` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-keysign-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-server` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-server-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-sk-dummy-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:9.9p1-13.el10_1 |
| `openssh-askpass` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |
| `openssh-askpass-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |
| `openssh-cavs-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |
| `openssh-clients-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |
| `openssh-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |
| `openssh-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.0p1-28.el8_10 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, OpenSSH, Redhat Enterprise Linux.

## How do I fix CVE-2026-3497?

Apply the vendor's patch.

## Is CVE-2026-3497 being exploited?

There is no known exploitation of CVE-2026-3497 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3497 and fix it if it is affected.

What it is: CVE-2026-3497 is a low-severity vulnerability in Canonical Ubuntu Linux, published on 12 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-3497 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2026-3497/ (Markdown: https://insights.sbomify.com/CVE-2026-3497/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3497
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3497
- OSV: https://osv.dev/vulnerability/CVE-2026-3497

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3497/
Summaries are generated and may contain mistakes; the official description above is the record.