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

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.

CVSS

2.5 LOW (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

Weakness (CWE)

CWE-93, CWE-94, CWE-150

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

GitHub_M

NVD analysis

Awaiting Analysis

Record last updated

Oct 15, 2026

First seen by InfoSec Signals

Oct 15, 2026

The CVE record on cve.org · NVD's entry

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