{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-105242", "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09", "state": "PUBLISHED", "assignerShortName": "apache", "dateReserved": "2026-10-04T16:21:12.546Z", "datePublished": "2026-10-06T19:50:19.075Z", "dateUpdated": "2026-10-06T19:50:19.075Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09", "shortName": "apache", "dateUpdated": "2026-10-06T19:50:19.075Z"}, "title": "Apache log4net: Request validation failure drops the event in the aspnet-request converter", "problemTypes": [{"descriptions": [{"description": "CWE-755 Improper Handling of Exceptional Conditions", "lang": "en", "cweId": "CWE-755", "type": "CWE"}]}], "source": {"discovery": "INTERNAL"}, "affected": [{"vendor": "Apache Software Foundation", "product": "Apache log4net", "packageURL": "pkg:nuget/log4net", "versions": [{"status": "affected", "version": "1.2.11", "lessThan": "3.5.0", "versionType": "semver"}], "defaultStatus": "unaffected", "collectionURL": "https://nuget.org/packages", "packageName": "log4net"}, {"vendor": "Apache Software Foundation", "product": "Apache log4net", "packageURL": "pkg:nuget/log4net", "repo": "https://gitbox.apache.org/repos/asf/logging-log4net.git", "versions": [{"status": "affected", "version": "243f1e9f3ee235955bade4b4fe664a903378719a", "lessThan": "145203420c579a703008b4b723b6a080757f4964", "versionType": "git"}], "defaultStatus": "unaffected", "collectionURL": "https://nuget.org/packages", "packageName": "log4net"}], "descriptions": [{"value": "Improper Handling of Exceptional Conditions vulnerability in the aspnet-request pattern converter of Apache log4net.\n\nReading request parameters triggers ASP.NET request validation, so a request carrying content such as markup made the layout throw and the appender discarded the whole event. A sender could suppress the log record of their own request. Only applications on ASP.NET for .NET Framework whose layout uses %aspnet-request are affected.\n\nThis issue affects Apache log4net: from 1.2.11 before 3.5.0.\n\nUsers are recommended to upgrade to version 3.5.0, which fixes the issue.", "lang": "en", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Improper Handling of Exceptional Conditions vulnerability in the aspnet-request pattern converter of Apache log4net.<br><br>Reading request parameters triggers ASP.NET request validation, so a request carrying content such as markup made the layout throw and the appender discarded the whole event. A sender could suppress the log record of their own request. Only applications on ASP.NET for .NET Framework whose layout uses %aspnet-request are affected.<br><br>This issue affects Apache log4net: from 1.2.11 before 3.5.0.<br><br>Users are recommended to upgrade to version 3.5.0, which fixes the issue."}]}], "references": [{"url": "https://github.com/apache/logging-log4net/pull/316", "tags": ["patch"]}, {"url": "https://github.com/apache/logging-log4net/commit/145203420c579a703008b4b723b6a080757f4964", "tags": ["patch"]}, {"url": "https://lists.apache.org/thread.html/zg6dbqm4ztm7j3c21nfsqj0yxm5yrpdx", "tags": ["vendor-advisory"]}], "metrics": [{"other": {"type": "Textual description of severity", "content": {"text": "moderate"}}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"scenarios": [{"lang": "en", "value": "GENERAL"}], "format": "CVSS", "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseSeverity": "MEDIUM", "baseScore": 5.3, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"}}], "credits": [{"lang": "en", "value": "The Apache Software Foundation", "type": "finder"}, {"lang": "en", "value": "Claude Security", "type": "tool"}, {"lang": "en", "value": "Jan Friedrich", "type": "remediation developer"}], "x_generator": {"engine": "Vulnogram 1.0.3"}}}}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.2.11,3.5.0)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Apache log4net", "source": "cna", "vendor": "Apache Software Foundation"}, "product": "log4net", "vendor": "apache"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[243f1e9f3ee235955bade4b4fe664a903378719a,145203420c579a703008b4b723b6a080757f4964)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Apache log4net", "source": "cna", "vendor": "Apache Software Foundation"}, "product": "log4net", "vendor": "apache"}], "created": "2026-10-06T23:00:08.103167+00:00", "updated": "2026-10-06T23:00:08.103214+00:00", "vendors": ["apache", "apache$PRODUCT$log4net"]}