{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-4437", "tracking": { "current_release_date": "2026-03-31T06:30:22.870764Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-4437", "initial_release_date": "2026-03-20T20:25:51.162019Z", "revision_history": [ { "date": "2026-03-20T20:25:51.162019Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| References created (1).| CWES updated (1)." }, { "date": "2026-03-20T20:25:53.607051Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-20T20:39:14.481952Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products created (1).| References created (1).| CWES updated (1)." }, { "date": "2026-03-20T20:39:20.405797Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-21T00:43:22.206859Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Products connected (2)." }, { "date": "2026-03-21T06:43:15.365247Z", "number": "6", "summary": "Description created for source." }, { "date": "2026-03-21T15:20:23.190944Z", "number": "7", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-21T15:20:29.254868Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-03-23T06:19:55.315423Z", "number": "9", "summary": "Source connected.| CVE status created. (valid)| Description created for source.| Products connected (1).| CWES updated (1)." }, { "date": "2026-03-23T12:29:48.417800Z", "number": "10", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (14).| Product Identifiers created (6).| Product Remediations created (14).| References created (3).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-03-23T12:29:52.733919Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-03-23T13:46:27.395967Z", "number": "12", "summary": "Source created.| CVE status created. (valid)| Products created (1).| Product Identifiers created (1).| References created (6)." }, { "date": "2026-03-23T13:46:41.979135Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-03-23T22:27:44.673119Z", "number": "14", "summary": "CVSS created.| Unknown change." }, { "date": "2026-03-23T22:27:47.265667Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-03-24T02:16:48.664875Z", "number": "16", "summary": "CVSS created." }, { "date": "2026-03-24T02:16:51.096559Z", "number": "17", "summary": "NCSC Score updated." }, { "date": "2026-03-24T09:56:43.363231Z", "number": "18", "summary": "CVSS created." }, { "date": "2026-03-24T09:56:51.216283Z", "number": "19", "summary": "NCSC Score updated." }, { "date": "2026-03-25T12:19:56.182856Z", "number": "20", "summary": "Products connected (1)." }, { "date": "2026-03-25T12:20:00.401300Z", "number": "21", "summary": "NCSC Score updated." }, { "date": "2026-03-27T06:19:51.527338Z", "number": "22", "summary": "Products removed (1)." }, { "date": "2026-03-27T06:20:00.460996Z", "number": "23", "summary": "NCSC Score updated." }, { "date": "2026-03-27T19:40:22.251031Z", "number": "24", "summary": "Products connected (1)." }, { "date": "2026-03-27T19:40:27.114161Z", "number": "25", "summary": "NCSC Score updated." }, { "date": "2026-03-29T12:19:49.363171Z", "number": "26", "summary": "Product Remediations created (1)." }, { "date": "2026-03-29T12:20:05.775625Z", "number": "27", "summary": "NCSC Score updated." }, { "date": "2026-03-31T06:28:02.178525Z", "number": "28", "summary": "NCSC Score updated." } ], "status": "interim", "version": "28" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/2.34-2.43", "product": { "name": "vers:unknown/2.34-2.43", "product_id": "CSAFPID-5892267", "product_identification_helper": { "cpe": "cpe:/a:gnu:glibc:2.34_-_2.43" } } } ], "category": "product_name", "name": "GNU libc" } ], "category": "vendor", "name": "Open Source" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/10", "product": { "name": "vers:rpm/10", "product_id": "CSAFPID-2858634", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:10" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 10" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/6", "product": { "name": "vers:rpm/6", "product_id": "CSAFPID-1439321", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:6" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 6" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/7", "product": { "name": "vers:rpm/7", "product_id": "CSAFPID-1439315", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:7" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 7" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/8", "product": { "name": "vers:rpm/8", "product_id": "CSAFPID-1439317", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:8" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 8" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/9", "product": { "name": "vers:rpm/9", "product_id": "CSAFPID-1439319", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:9" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 9" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/4", "product": { "name": "vers:rpm/4", "product_id": "CSAFPID-1439328", "product_identification_helper": { "cpe": "cpe:/a:redhat:openshift:4" } } } ], "category": "product_name", "name": "Red Hat OpenShift Container Platform 4" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441502" } } ], "category": "product_name", "name": "compat-glibc" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441503" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 6" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441504" } } ], "category": "product_name", "name": "compat-glibc" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441505" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 7" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-2898794" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 10" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441506" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 8" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1441507" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 9" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1439329" } } ], "category": "product_name", "name": "rhcos" } ], "category": "product_family", "name": "Red Hat OpenShift Container Platform 4" } ], "category": "vendor", "name": "Red Hat" }, { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:microsoft/*", "product": { "name": "vers:microsoft/*", "product_id": "CSAFPID-5890851", "product_identification_helper": { "cpe": "cpe:2.3:a:microsoft:azl3_glibc_2.38-18:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "azl3 glibc 2.38-18 on Azure Linux 3.0" }, { "branches": [ { "category": "product_version_range", "name": "vers:microsoft/*", "product": { "name": "vers:microsoft/*", "product_id": "CSAFPID-5826718", "product_identification_helper": { "cpe": "cpe:2.3:a:microsoft:cbl2_glibc_2.35-10:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "cbl2 glibc 2.35-10 on CBL Mariner 2.0" } ], "category": "product_family", "name": "Open Source Software" } ], "category": "vendor", "name": "Microsoft" }, { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-1398444" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "bookworm" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-1398441" } } ], "category": "product_name", "name": "glibc" } ], "category": "product_family", "name": "bullseye" } ], "category": "vendor", "name": "Debian" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/2.34|<=2.43", "product": { "name": "vers:unknown/2.34|<=2.43", "product_id": "CSAFPID-5875874" } } ], "category": "product_name", "name": "glibc" } ], "category": "vendor", "name": "The GNU C Library" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-4437", "cwe": { "id": "CWE-125", "name": "Out-of-bounds Read" }, "notes": [ { "category": "description", "text": "Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-4437" }, { "category": "description", "text": "Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/4xxx/CVE-2026-4437.json" }, { "category": "description", "text": "Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-4437" }, { "category": "description", "text": "gethostbyaddr and gethostbyaddr\\_r may incorrectly handle DNS response", "title": "microsoft - https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Mar" }, { "category": "description", "text": "A flaw was found in glibc (the GNU C Library). When an application uses the `gethostbyaddr` or `gethostbyaddr_r` functions with a `nsswitch.conf` configuration that specifies glibc's DNS backend, a remote attacker can send a specially crafted DNS (Domain Name System) response. This crafted response can cause the application to incorrectly interpret a non-answer section of the DNS response as a valid answer, leading to potential misbehavior or incorrect information processing.\nThis MODERATE impact flaw in glibc allows a remote attacker to send a specially crafted DNS response when an application uses `gethostbyaddr` or `gethostbyaddr_r` with glibc's DNS backend configured in `nsswitch.conf`. This can lead to incorrect interpretation of DNS responses. Red Hat Enterprise Linux versions 6, 7, 8, 9, and 10, as well as OpenShift Container Platform, are affected if applications are configured to use the vulnerable DNS backend.", "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-4437.json" }, { "category": "other", "text": "0.00018", "title": "EPSS" }, { "category": "other", "text": "3.9", "title": "NCSC Score" }, { "category": "other", "text": "VENDOR FIX as product remediation category, There is product data available from source Certbundde", "title": "NCSC Score top increasing factors" }, { "category": "other", "text": "There is cwe data available from source Nvd, Is related to a product by vendor Red Hat, There is product data available from source Debian, Is related to a product by vendor Open Source", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 2\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-5875874", "CSAFPID-1398441", "CSAFPID-1398444", "CSAFPID-5890851", "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-1441502", "CSAFPID-1441503", "CSAFPID-1441504", "CSAFPID-1441505", "CSAFPID-1441506", "CSAFPID-1441507", "CSAFPID-2858634", "CSAFPID-2898794", "CSAFPID-5892267", "CSAFPID-5826718" ] }, "references": [ { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-4437" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/4xxx/CVE-2026-4437.json" }, { "category": "external", "summary": "Source - debian", "url": "https://security-tracker.debian.org/tracker/CVE-2026-4437" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - microsoft", "url": "https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2026-Mar" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-4437.json" }, { "category": "external", "summary": "Source - certbundde", "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0817.json" }, { "category": "external", "summary": "Reference - certbundde; cveprojectv5; nvd; redhat", "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34014" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-4437" }, { "category": "external", "summary": "Reference - certbundde; redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4437" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0817.json" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0817" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4438" }, { "category": "external", "summary": "Reference - certbundde", "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34015" } ], "remediations": [ { "category": "mitigation", "details": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.", "product_ids": [ "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-1441502", "CSAFPID-1441503", "CSAFPID-1441504", "CSAFPID-1441505", "CSAFPID-1441506", "CSAFPID-1441507", "CSAFPID-2858634", "CSAFPID-2898794" ] }, { "category": "vendor_fix", "details": "CBL-Mariner Releases", "product_ids": [ "CSAFPID-5890851" ] } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "products": [ "CSAFPID-1398441", "CSAFPID-1398444", "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439321", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-1441502", "CSAFPID-1441503", "CSAFPID-1441504", "CSAFPID-1441505", "CSAFPID-1441506", "CSAFPID-1441507", "CSAFPID-2858634", "CSAFPID-2898794", "CSAFPID-5826718", "CSAFPID-5875874", "CSAFPID-5890851", "CSAFPID-5892267" ] } ], "title": "CVE-2026-4437" } ] }