Vulnerability · Published Oct 15, 2026 · Assigned by GitHub_M
CVE-2026-55467CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)
Low 2.5
In plain English
A low-severity code injection in cups from OpenPrinting. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cups | no fix listed | DEBIAN-CVE-2026-55467 |
| Debian:13 | cups | no fix listed | DEBIAN-CVE-2026-55467 |
| Debian:14 | cups | no fix listed | DEBIAN-CVE-2026-55467 |
| Ubuntu:22.04:LTS | cups-filters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:24.04:LTS | cups-filters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:26.04:LTS | cups-filters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:26.10 | cups-filters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:24.04:LTS | libcupsfilters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:26.04:LTS | libcupsfilters | no fix listed | UBUNTU-CVE-2026-55467 |
| Ubuntu:26.10 | libcupsfilters | no fix listed | UBUNTU-CVE-2026-55467 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| OpenPrinting | cups | < 2.4.20 |
Weakness: CWE-93, CWE-94, CWE-150 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
References
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7 x_refsource_CONFIRM
- https://github.com/OpenPrinting/cups/commit/0cf4e7814d6810ed3c454222bce3aa342d541681 x_refsource_MISC
- https://github.com/OpenPrinting/cups/commit/a9e7e7a3a019d0fa063d29409d3f82e4c6d5a008 x_refsource_MISC
- https://github.com/OpenPrinting/cups/releases/tag/v2.4.20 x_refsource_MISC