# CVE-2026-105326: Cups: cups: argument injection in mailto notifier via notify-recipient-uri

> Remote attackers can execute arbitrary commands via argument injection in CUPS mailto notifier when email notifications are enabled.

- **Severity:** Low 2.5 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **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:** 5 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** AZL-106743, BELL-CVE-2026-105326, DEBIAN-CVE-2026-105326, ECHO-b398-2098-0d6b, GHSA-r4wf-366f-f6g3, RHSA-2026:77638, UBUNTU-CVE-2026-105326

## What is CVE-2026-105326?

CVE-2026-105326 is a low-severity command injection vulnerability in Red Hat Enterprise Linux 10, published on 5 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An argument injection flaw was found in CUPS. When email notification is configured, the CUPS scheduler accepts printer subscription requests that supply a mailto notify-recipient-uri. The mailto notifier passes the recipient address to the configured sendmail program without ensuring it cannot be interpreted as command-line options. A remote attacker who can reach the CUPS service could supply a crafted recipient value starting with "-" to influence sendmail behavior. Successful exploitation depends on the installed mail transfer agent and CUPS network exposure, and may lead to execution of attacker-controlled commands with the privileges of the CUPS service user.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command)

## Which versions are affected by CVE-2026-105326?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `cups` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-client` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-devel` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-filesystem` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-ipptool` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-libs` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-lpd` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |
| `cups-printerapp` | Red Hat:hummingbird:1 | All versions | 0:2.4.19-4.3.hum1 |

## How do I fix CVE-2026-105326?

Apply the vendor's patch.

## Is CVE-2026-105326 being exploited?

There is no known exploitation of CVE-2026-105326 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105326 and fix it if it is affected.

What it is: CVE-2026-105326 is a low-severity command injection vulnerability in Red Hat Enterprise Linux 10, published on 5 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-2026-105326 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-2026-105326/ (Markdown: https://insights.sbomify.com/CVE-2026-105326/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105326
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105326
- OSV: https://osv.dev/vulnerability/CVE-2026-105326

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105326/
Summaries are generated and may contain mistakes; the official description above is the record.