{"id":"CVE-2026-55467","state":"PUBLISHED","title":"CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)","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.","publishedAt":"2026-10-15T17:08:24.374Z","updatedAt":"2026-10-15T17:49:26.673Z","severity":{"score":2.5,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["OpenPrinting cups"],"affected":[{"vendor":"OpenPrinting","product":"cups","versions":[{"version":"< 2.4.20","status":"affected"}]}],"references":["https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7","https://github.com/OpenPrinting/cups/commit/0cf4e7814d6810ed3c454222bce3aa342d541681","https://github.com/OpenPrinting/cups/commit/a9e7e7a3a019d0fa063d29409d3f82e4c6d5a008","https://github.com/OpenPrinting/cups/releases/tag/v2.4.20"],"weaknesses":["CWE-93","CWE-94","CWE-150"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55467.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55467","state":"PUBLISHED","datePublished":"2026-10-15T17:08:24.374Z","dateUpdated":"2026-10-15T17:49:26.673Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T22:10:37.608Z"},"containers":{"cna":{"title":"CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)","descriptions":[{"lang":"en","value":"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":[{"vendor":"OpenPrinting","product":"cups","versions":[{"version":"< 2.4.20","status":"affected"}]}],"references":[{"url":"https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7","name":"https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/OpenPrinting/cups/commit/0cf4e7814d6810ed3c454222bce3aa342d541681","name":"https://github.com/OpenPrinting/cups/commit/0cf4e7814d6810ed3c454222bce3aa342d541681","tags":["x_refsource_MISC"]},{"url":"https://github.com/OpenPrinting/cups/commit/a9e7e7a3a019d0fa063d29409d3f82e4c6d5a008","name":"https://github.com/OpenPrinting/cups/commit/a9e7e7a3a019d0fa063d29409d3f82e4c6d5a008","tags":["x_refsource_MISC"]},{"url":"https://github.com/OpenPrinting/cups/releases/tag/v2.4.20","name":"https://github.com/OpenPrinting/cups/releases/tag/v2.4.20","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"LOW","baseScore":2.5,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-93","lang":"en","description":"CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code ('Code Injection')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-150","lang":"en","description":"CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-15T17:08:24.374Z"},"source":{"advisory":"GHSA-69qc-prxg-h2c7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/OpenPrinting/cups/security/advisories/GHSA-69qc-prxg-h2c7","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T17:49:04.144102Z","id":"CVE-2026-55467","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T17:49:26.673Z"}}]}}}