CVE-2026-105243

{"id": "CVE-2026-105243", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-105243", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-07T14:49:30.641089Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@apache.org", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@apache.org", "affectedData": [{"vendor": "Apache Software Foundation", "product": "Apache log4net", "versions": [{"status": "affected", "version": "1.2.9", "lessThan": "3.5.0", "versionType": "semver"}], "packageURL": "pkg:nuget/log4net", "packageName": "log4net", "collectionURL": "https://nuget.org/packages", "defaultStatus": "unaffected"}, {"repo": "https://gitbox.apache.org/repos/asf/logging-log4net.git", "vendor": "Apache Software Foundation", "product": "Apache log4net", "versions": [{"status": "affected", "version": "02e1e115435888485f2e28b414d267e39e799e07", "lessThan": "28fbfb25678c48a8cc5bc9b94ead0dddfc39ffed", "versionType": "git"}], "packageURL": "pkg:nuget/log4net", "packageName": "log4net", "collectionURL": "https://nuget.org/packages", "defaultStatus": "unaffected"}]}], "published": "2026-10-06T20:17:16.167", "references": [{"url": "https://github.com/apache/logging-log4net/commit/28fbfb25678c48a8cc5bc9b94ead0dddfc39ffed", "tags": ["Patch"], "source": "security@apache.org"}, {"url": "https://github.com/apache/logging-log4net/pull/315", "tags": ["Patch"], "source": "security@apache.org"}, {"url": "https://lists.apache.org/thread.html/jr6fj5skv1vnjbc9jmt8bp151p8ow1rp", "tags": ["Mailing List", "Vendor Advisory"], "source": "security@apache.org"}, {"url": "http://www.openwall.com/lists/oss-security/2026/10/07/17", "tags": ["Mailing List", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@apache.org", "description": [{"lang": "en", "value": "CWE-778"}]}], "descriptions": [{"lang": "en", "value": "Insufficient Logging vulnerability in the EventLogAppender of Apache log4net.\n\nLong messages were truncated to a fixed size that exceeds what the Windows Event Log accepts once the log and source names are counted, and the event log then stored nothing and reported nothing. A party whose data reaches a log message could suppress the whole record by making it long enough. Only applications on Windows that use EventLogAppender are affected.\n\nThis issue affects Apache log4net: from 1.2.9 before 3.5.0.\n\nUsers are recommended to upgrade to version 3.5.0, which fixes the issue."}], "lastModified": "2026-10-09T15:26:03.430", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:log4net:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "182F45E2-D20D-4B67-85C1-AFE1D39A5692", "versionEndExcluding": "3.5.0", "versionStartIncluding": "1.2.9"}], "operator": "OR"}]}], "sourceIdentifier": "security@apache.org"}