High
Security advisory
Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-11993
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:24 UTC · Revision 1
Source evidence
Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.
osv:CVE-2020-11993
Complete source record
{
"id": "799344b2b8f24c9bbfcaf6ca7e3c001f6874936f4f568d74e61c47af50ba0cfc",
"url": "https://osv.dev/vulnerability/CVE-2020-11993",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-11993",
"summary": "Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above \"info\" will mitigate this vulnerability for unpatched servers.",
"evidence": "osv:CVE-2020-11993",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-11993",
"aliases": [
"BIT-apache-2020-11993",
"CVE-2020-11993"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/apache/httpd",
"type": "GIT",
"events": [
{
"introduced": "6e65a7f3dadcade4274ae53f734d4c35188e3786"
},
{
"fixed": "fb2bfbb77f1713d4f4e56b0e60d596d302befe99"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2.4.20"
},
{
"fixed": "2.4.44"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-11993.json"
}
}
],
"modified": "2026-10-24T10:31:07.142322587Z",
"provider": "osv",
"references": [
"https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2020-11993",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NKWG2EXAQQB6LMLATKZ7KLSRGCSHVAN/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVFDBVM6E3JF3O7RYLRPRCH3RDRHJJY/",
"https://security.gentoo.org/glsa/202008-04",
"https://security.netapp.com/advisory/ntap-20200814-0005/",
"https://usn.ubuntu.com/4458-1/",
"https://www.debian.org/security/2020/dsa-4757",
"https://www.oracle.com/security-alerts/cpujan2021.html",
"https://www.oracle.com/security-alerts/cpuoct2020.html",
"https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r09bb998baee74a2c316446bd1a41ae7f8d7049d09d9ff991471e8775%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r2c6083f6a2027914a0f5b54e2a1f4fa98c03f8693b58460911818255%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r3c5c3104813c1c5508b55564b66546933079250a46ce50eee90b2e36%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r5debe8f82728a00a4a68bc904dd6c35423bdfc8d601cfb4579f38bf1%40%3Cdev.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r623de9b2b2433a87f3f3a15900419fc9c00c77b26936dfea4060f672%40%3Cdev.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r9e9f1a7609760f0f80562eaaec2aa3c32d525c3e0fca98b475240c71%40%3Cdev.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/rdf3e5d0a5f5c3d90d6013bccc6c4d5af59cf1f8c8dea5d9a283d13ce%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E",
"https://lists.apache.org/thread.html/rf71eb428714374a6f9ad68952e23611ec7807b029fd6a1b4f5f732d9%40%3Ccvs.httpd.apache.org%3E"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:oracle:communications_element_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_element_manager",
"extracted_events": [
{
"range": [
{
"introduced": "8.2.0"
},
{
"last_affected": "8.2.2"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_session_report_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_session_report_manager",
"extracted_events": [
{
"range": [
{
"introduced": "8.2.0"
},
{
"last_affected": "8.2.2"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_session_route_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_session_route_manager",
"extracted_events": [
{
"range": [
{
"introduced": "8.2.0"
},
{
"last_affected": "8.2.2"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "16.04"
},
{
"last_affected": "16.04"
},
{
"introduced": "18.04"
},
{
"last_affected": "18.04"
},
{
"introduced": "20.04"
},
{
"last_affected": "20.04"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "31"
},
{
"last_affected": "31"
},
{
"introduced": "32"
},
{
"last_affected": "32"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*",
"cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*"
],
"vendor_product": "opensuse:leap",
"extracted_events": [
{
"range": [
{
"introduced": "15.1"
},
{
"last_affected": "15.1"
},
{
"introduced": "15.2"
},
{
"last_affected": "15.2"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:enterprise_manager_ops_center",
"extracted_events": [
{
"range": [
{
"introduced": "12.4.0.0"
},
{
"last_affected": "12.4.0.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:hyperion_infrastructure_technology:11.1.2.4:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:hyperion_infrastructure_technology",
"extracted_events": [
{
"range": [
{
"introduced": "11.1.2.4"
},
{
"last_affected": "11.1.2.4"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:instantis_enterprisetrack",
"extracted_events": [
{
"range": [
{
"introduced": "17.1"
},
{
"last_affected": "17.1"
},
{
"introduced": "17.2"
},
{
"last_affected": "17.2"
},
{
"introduced": "17.3"
},
{
"last_affected": "17.3"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:zfs_storage_appliance_kit",
"extracted_events": [
{
"range": [
{
"introduced": "8.8"
},
{
"last_affected": "8.8"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-11993",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 441138,
"published_at": "2020-08-07T16:15:11.887+00:00"
}