{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-104721", "assignerOrgId": "455daabc-a392-441d-aa46-37d35189897c", "state": "PUBLISHED", "assignerShortName": "NCSC.ch", "dateReserved": "2026-10-02T11:43:59.014Z", "datePublished": "2026-10-02T13:21:59.195Z", "dateUpdated": "2026-10-02T13:21:59.195Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "455daabc-a392-441d-aa46-37d35189897c", "shortName": "NCSC.ch", "dateUpdated": "2026-10-02T13:21:59.195Z"}, "title": "Logback: Incomplete protection against CVE-2026-19880", "datePublic": "2026-08-14T08:09:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-22", "description": "CWE-22", "type": "CWE"}]}], "impacts": [{"descriptions": [{"lang": "en", "value": "path-traversal vulnerability"}]}], "affected": [{"vendor": "QOS.CH Sarl", "product": "Logback-classic", "platforms": ["Java"], "modules": ["logback-classic"], "versions": [{"status": "affected", "version": "0.9.14", "lessThanOrEqual": "1.6.4", "versionType": "maven"}, {"status": "unaffected", "version": "1.6.5", "versionType": "maven"}], "defaultStatus": "affected"}], "descriptions": [{"lang": "en", "value": "Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an \nMDC-based discriminator value flows unsanitized into a nested \nFileAppender path, letting an attacker who influences that MDC value \n(e.g. via an HTTP header)\n create and append log files outside the intended directory. \n\n\nThis issue affects Logback-classic: from 0.9.14 through 1.6.4.\u00a0 This vulnerability is similar to CVE-2026-19880 but involves other attack techniques.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an \nMDC-based discriminator value flows unsanitized into a nested \nFileAppender path, letting an attacker who influences that MDC value \n(e.g. via an HTTP header)\n create and append log files outside the intended directory. <p><br>This issue affects Logback-classic: from 0.9.14 through 1.6.4.&nbsp; This vulnerability is similar to CVE-2026-19880 but involves other attack techniques.<br><br></p>"}]}], "references": [{"url": "https://logback.qos.ch/news.html#1.6.5"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "PRESENT", "Automatable": "NO", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "MODERATE", "providerUrgency": "GREEN", "version": "4.0", "baseSeverity": "MEDIUM", "baseScore": 6.3, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/S:P/AU:N/RE:M/U:Green"}}], "workarounds": [{"lang": "en", "value": "Update to logack version 1.6.5 or later.\u00a0This vulnerability requires\u00a0SiftingAppender\u00a0to be active as well as unsanitized data provided by an attacker that\u00a0MDCDiscriminator\u00a0makes use of.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Update to logack version 1.6.5 or later.&nbsp;This vulnerability requires&nbsp;<code>SiftingAppender</code>&nbsp;to be active as well as unsanitized data provided by an attacker that&nbsp;<code>MDCDiscriminator</code>&nbsp;makes use of."}]}], "solutions": [{"lang": "en", "value": "Update to logack version 1.6.5 or later.\u00a0This vulnerability requires\u00a0SiftingAppender\u00a0to be active as well as unsanitized data provided by an \nattacker that MDCDiscriminator makes use of.\u00a0\n\nSanitizing relevant data provided by the user should fix this vulnerability.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Update to logack version 1.6.5 or later.&nbsp;This vulnerability requires&nbsp;<code>SiftingAppender</code>&nbsp;to be active as well as unsanitized data provided by an \nattacker that MDCDiscriminator makes use of.&nbsp;<br><br>Sanitizing relevant data provided by the user should fix this vulnerability."}]}], "exploits": [{"lang": "en", "value": "No known exploitation", "supportingMedia": [{"type": "text/html", "base64": false, "value": "No known exploitation<br>"}]}], "credits": [{"lang": "en", "value": "Fran\u00e7ois Martin (GitHub: @martinfrancois, https://github.com/martinfrancois)", "type": "finder"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 0.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "affected", "modules": ["logback-classic"], "platforms": ["Java"], "product": "Logback-classic", "vendor": "QOS.CH Sarl", "versions": [{"lessThanOrEqual": "1.6.4", "status": "affected", "version": "0.9.14", "versionType": "maven"}, {"status": "unaffected", "version": "1.6.5", "versionType": "maven"}]}], "source": "vulnerability@ncsc.ch"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an \nMDC-based discriminator value flows unsanitized into a nested \nFileAppender path, letting an attacker who influences that MDC value \n(e.g. via an HTTP header)\n create and append log files outside the intended directory. \n\n\nThis issue affects Logback-classic: from 0.9.14 through 1.6.4.\u00a0 This vulnerability is similar to CVE-2026-19880 but involves other attack techniques."}], "id": "CVE-2026-104721", "lastModified": "2026-10-02T14:17:10.167", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NO", "Recovery": "NOT_DEFINED", "Safety": "PRESENT", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "GREEN", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:P/AU:N/R:X/V:X/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "MODERATE"}, "source": "vulnerability@ncsc.ch", "type": "Secondary"}]}, "published": "2026-10-02T14:17:10.167", "references": [{"source": "vulnerability@ncsc.ch", "url": "https://logback.qos.ch/news.html#1.6.5"}], "sourceIdentifier": "vulnerability@ncsc.ch", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}], "source": "vulnerability@ncsc.ch", "type": "Secondary"}]}

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{"created": "2026-10-02T15:15:07.795765+00:00", "updated": "2026-10-02T15:15:07.795772+00:00", "vendors": []}