CVE-2026-55467
CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low2.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Analyzed | 3.1 | Low2.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.5.
Weakness
- CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') (opens in a new tab)All about CWE-93 and its CVEs
- CWE-94: Improper Control of Generation of Code ('Code Injection') (opens in a new tab)All about CWE-94 and its CVEs
- CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences (opens in a new tab)All about CWE-150 and its CVEs
Affected products
- affected < 2.4.20
References (4)
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/OpenPrinting/cups/commit/0cf4e7814d6810ed3c454222bce3aa342d541681 (opens in a new tab)x_refsource_MISC
- https://github.com/OpenPrinting/cups/commit/a9e7e7a3a019d0fa063d29409d3f82e4c6d5a008 (opens in a new tab)x_refsource_MISC
- https://github.com/OpenPrinting/cups/releases/tag/v2.4.20 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55467)Record last updated .