# CVE-2026-55467: CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)

> An attacker with job submission privileges can inject control characters into fax options, potentially executing code or disrupting queues if vulnerable filters are used.

- **Severity:** Low 2.5 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **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:** 15 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-108278, BELL-CVE-2026-55467, DEBIAN-CVE-2026-55467, ECHO-f9e9-2edb-85ee, GHSA-69qc-prxg-h2c7, UBUNTU-CVE-2026-55467

## What is CVE-2026-55467?

CVE-2026-55467 is a low-severity command injection vulnerability in OpenPrinting cups, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the cupsdCreateJob option-string builder in scheduler/job.c maps attacker-controlled destination-uri and pre-dial-string values from a configured fax queue to the phone and faxPrefix options. Unlike ordinary IPP job attributes, these mapped fax values bypass the control-character sanitizer and are copied directly into the filter options argument. A user permitted to submit a job can therefore inject control characters into the downstream option stream. The reporter states that a downstream fax filter passing these values to a shell or modem command could execute code as lp, while the maintainer states that CUPS has no confidentiality or integrity impact because the only known code-executing filter is optional Foomatic and addressed separately, leaving possible disruption of the affected queue. This issue is fixed in version 2.4.20.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-93 (Improper Neutralization of CRLF Sequences), CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences)

## Which versions are affected by CVE-2026-55467?

It affects 1 product.


Products: Openprinting Cups.

## How do I fix CVE-2026-55467?

Upgrade to a fixed version.

## Is CVE-2026-55467 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55467 exists.

## Other vulnerabilities in OpenPrinting cups

- [CVE-2025-58060](https://insights.sbomify.com/CVE-2025-58060/): cups has Authentication bypass with AuthType Negotiate (high 8.0)
- [CVE-2026-34978](https://insights.sbomify.com/CVE-2026-34978/): Path traversal in cups (medium 6.5)
- [CVE-2025-58364](https://insights.sbomify.com/CVE-2025-58364/): cups: Remote DoS via null dereference (medium 6.5)
- [CVE-2026-34980](https://insights.sbomify.com/CVE-2026-34980/): OpenPrinting CUPS: Shared PostScript queue lets anonymous Print-Job requests reach `lp` code execution over the network (medium 6.1)
- [CVE-2025-61915](https://insights.sbomify.com/CVE-2025-61915/): OpenPrinting CUPS vulnerable to stack based out-of-bound write (medium 6.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55467 and fix it if it is affected.

What it is: CVE-2026-55467 is a low-severity command injection vulnerability in OpenPrinting cups, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55467 exists.

Affected product: OpenPrinting cups. 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-2026-55467/ (Markdown: https://insights.sbomify.com/CVE-2026-55467/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55467
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55467
- OSV: https://osv.dev/vulnerability/CVE-2026-55467

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55467/
Summaries are generated and may contain mistakes; the official description above is the record.