CVE-2026-104721

{"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"}}}}

{}

{"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": "2026-10-02T17:59:09.430", "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": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}], "source": "vulnerability@ncsc.ch", "type": "Secondary"}]}

{"bugzilla": {"description": "ch.qos.logback/logback-classic: logback-classic: Arbitrary file write via path traversal in MDC discriminator", "id": "2545184", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2545184"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.6", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "status": "draft"}, "cwe": "CWE-22", "details": ["A flaw was found in logback-classic. This path traversal vulnerability allows a remote attacker to create and append log files outside the intended directory. The issue occurs when an unsanitized Mapped Diagnostic Context (MDC) discriminator value flows into a nested log file path, enabling an attacker who can influence this context, such as through an HTTP request header, to manipulate the destination file location."], "name": "CVE-2026-104721", "package_state": [{"cpe": "cpe:/a:redhat:migration_toolkit_applications:8", "fix_state": "Fix deferred", "package_name": "mta/mta-cli-rhel9", "product_name": "Migration Toolkit for Applications 8"}, {"cpe": "cpe:/a:redhat:migration_toolkit_applications:8", "fix_state": "Fix deferred", "package_name": "mta/mta-java-external-provider-rhel9", "product_name": "Migration Toolkit for Applications 8"}, {"cpe": "cpe:/a:redhat:serverless:1", "fix_state": "Fix deferred", "package_name": "openshift-serverless-1/kn-ekb-dispatcher-rhel9", "product_name": "OpenShift Serverless"}, {"cpe": "cpe:/a:redhat:serverless:1", "fix_state": "Fix deferred", "package_name": "openshift-serverless-1/kn-ekb-receiver-rhel9", "product_name": "OpenShift Serverless"}, {"cpe": "cpe:/a:redhat:apache_camel_hawtio:4", "fix_state": "Fix deferred", "package_name": "logback-classic", "product_name": "Red Hat build of Apache Camel - HawtIO 4"}, {"cpe": "cpe:/a:redhat:ceph_storage:9", "fix_state": "Fix deferred", "package_name": "libarrow", "product_name": "Red Hat Ceph Storage 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "apache-commons-logging", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "easymock", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "sisu", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "groovy", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "javapackages-tools:201801/maven", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "maven:3.8/sisu", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "maven:3.8/slf4j", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "easymock", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "maven:3.9/maven", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "maven:3.9/sisu", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "sisu", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "maven3.9", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_web_server:7", "fix_state": "Fix deferred", "package_name": "jws7-jboss-logging", "product_name": "Red Hat JBoss Web Server 7"}, {"cpe": "cpe:/a:redhat:openshift_devspaces:3", "fix_state": "Fix deferred", "package_name": "devspaces/openvsx-rhel9", "product_name": "Red Hat OpenShift Dev Spaces"}, {"cpe": "cpe:/a:redhat:openshift_devspaces:3", "fix_state": "Fix deferred", "package_name": "devspaces/pluginregistry-rhel9", "product_name": "Red Hat OpenShift Dev Spaces"}, {"cpe": "cpe:/a:redhat:openshift_devspaces:3", "fix_state": "Fix deferred", "package_name": "devspaces/server-rhel9", "product_name": "Red Hat OpenShift Dev Spaces"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Fix deferred", "package_name": "candlepin", "product_name": "Red Hat Satellite 6"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Fix deferred", "package_name": "openvox-server", "product_name": "Red Hat Satellite 6"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Fix deferred", "package_name": "puppetserver", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-10-02T13:21:59Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-104721\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-104721\nhttps://logback.qos.ch/news.html#1.6.5"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": ["java"], "status": "affected", "versions": {"scheme": "semver", "value": "[0.9.14,1.6.4]"}}, {"platform": ["java"], "status": "unaffected", "versions": {"scheme": "semver", "value": "1.6.5"}}], "enrichment": {"confidence": 90.0, "confidence_source": "matching", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 90.0, "source": "matching"}]}, "original": {"product": "Logback-classic", "source": "cna", "vendor": "QOS.CH Sarl"}, "product": "logback-classic", "vendor": "qos.ch_sarl"}], "created": "2026-10-02T15:15:07.795765+00:00", "updated": "2026-10-04T20:30:18.542670+00:00", "vendors": ["qos.ch_sarl", "qos.ch_sarl$PRODUCT$logback-classic"]}