{"id":"CVE-2026-1225","state":"PUBLISHED","title":"Malicious logback.xml configuration file allows instantiation of arbitrary classes","description":"ACE vulnerability in configuration file processing  by QOS.CH logback-core up to and including version 1.5.24 in Java applications, allows an attacker to instantiate classes already present on the class path by compromising an existing logback configuration file.\n\n\n\n\nThe instantiation of a potentially malicious Java class requires that said class is present on the user's class-path. In addition, the attacker must  have write access to a \nconfiguration file. However, after successful instantiation, the instance is very likely to be discarded with no further ado.","publishedAt":"2026-01-22T09:24:14.634Z","updatedAt":"2026-01-22T14:14:17.842Z","severity":{"score":1.8,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/S:N/AU:N/RE:M/U:Green","source":"NCSC.ch"},"assigner":"NCSC.ch","products":["QOS.CH Sarl Logback-core"],"affected":[{"vendor":"QOS.CH Sarl","product":"Logback-core","defaultStatus":"unknown","versions":[{"version":"0.9.20","status":"affected","lessThanOrEqual":"1.5.24","versionType":"maven"},{"version":"1.5.25","status":"unaffected"}],"modules":["logback-core","logback-classic"],"platforms":["Java"]}],"references":["https://logback.qos.ch/news.html#1.5.25"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/1xxx/CVE-2026-1225.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-1225","state":"PUBLISHED","datePublished":"2026-01-22T09:24:14.634Z","dateUpdated":"2026-01-22T14:14:17.842Z","assignerShortName":"NCSC.ch","assignerOrgId":"455daabc-a392-441d-aa46-37d35189897c","dateReserved":"2026-01-20T12:29:25.357Z"},"containers":{"cna":{"title":"Malicious logback.xml configuration file allows instantiation of arbitrary classes","descriptions":[{"lang":"en","value":"ACE vulnerability in configuration file processing  by QOS.CH logback-core up to and including version 1.5.24 in Java applications, allows an attacker to instantiate classes already present on the class path by compromising an existing logback configuration file.\n\n\n\n\nThe instantiation of a potentially malicious Java class requires that said class is present on the user's class-path. In addition, the attacker must  have write access to a \nconfiguration file. However, after successful instantiation, the instance is very likely to be discarded with no further ado."}],"affected":[{"vendor":"QOS.CH Sarl","product":"Logback-core","defaultStatus":"unknown","versions":[{"version":"0.9.20","status":"affected","lessThanOrEqual":"1.5.24","versionType":"maven"},{"version":"1.5.25","status":"unaffected"}],"modules":["logback-core","logback-classic"],"platforms":["Java"]}],"references":[{"url":"https://logback.qos.ch/news.html#1.5.25"}],"metrics":[{"cvssV4_0":{"Automatable":"NO","Recovery":"NOT_DEFINED","Safety":"NEGLIGIBLE","attackComplexity":"HIGH","attackRequirements":"PRESENT","attackVector":"LOCAL","baseScore":1.8,"baseSeverity":"LOW","exploitMaturity":"NOT_DEFINED","privilegesRequired":"HIGH","providerUrgency":"GREEN","subAvailabilityImpact":"LOW","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/S:N/AU:N/RE:M/U:Green","version":"4.0","vulnAvailabilityImpact":"LOW","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"MODERATE"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"CWE-20 Improper Input Validation","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"NCSC.ch","orgId":"455daabc-a392-441d-aa46-37d35189897c","dateUpdated":"2026-01-22T12:10:39.562Z"},"credits":[{"lang":"en","type":"finder","value":"https://www.code-intelligence.com/"},{"lang":"en","type":"finder","value":"Google Fuzz"}],"exploits":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"No known exploitation<br>"}],"value":"No known exploitation"}],"impacts":[{"descriptions":[{"lang":"en","value":"Arbitrary code execution on previously compromised system"}]},{"capecId":"CAPEC-242","descriptions":[{"lang":"en","value":"CAPEC-242 Code Injection"}]}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Update to logback version 1.5.25 or later. <br>"}],"value":"Update to logback version 1.5.25 or later."}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-22T14:14:09.436515Z","id":"CVE-2026-1225","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-22T14:14:17.842Z"}}]}}}