# CVE-2023-4806: Glibc: potential use-after-free in getaddrinfo() Status: published. Published: 2023-09-18. Updated: 2026-11-07. A flaw has been identified in glibc. In an extremely rare situation, the getaddrinfo function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the _nss_*_gethostbyname2_r and _nss_*_getcanonname_r hooks without implementing the _nss_*_gethostbyname3_r hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags. ## Remediation No remediation reported in collected sources ## Affected products and versions - Red Hat / Red Hat Enterprise Linux 8 (glibc): ≥ 0:2.28-225.el8_8.6; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 8.6 Extended Update Support (glibc): ≥ 0:2.28-189.8.el8_6; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 9 (glibc): ≥ 0:2.34-60.el9_2.7; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 (glibc): ≥ 0:2.28-189.8.el8_6; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 6 (compat-glibc): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 6 (glibc): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 7 (compat-glibc): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 7 (glibc): Version range not reported. Source: CNA: redhat - Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP - Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP - Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP ## Severity and prioritization - CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat - CISA KEV: No listing in collected sources - EPSS: 1.61% as of 2026-11-06; percentile 75.99% - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-416 ## Exploit evidence No exploit evidence in collected sources. This is not proof of no exploitation. ## References - https://access.redhat.com/errata/RHSA-2023:5453 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2023:5455 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/errata/RHSA-2023:7409 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/security/cve/CVE-2023-4806 (CNA: redhat; vdb-entry, x_refsource_REDHAT) - https://bugzilla.redhat.com/show_bug.cgi?id=2237782 (CNA: redhat; issue-tracking, x_refsource_REDHAT) - http://www.openwall.com/lists/oss-security/2023/10/03/4 (ADP: CVE; x_transferred) - http://www.openwall.com/lists/oss-security/2023/10/03/5 (ADP: CVE; x_transferred) - http://www.openwall.com/lists/oss-security/2023/10/03/6 (ADP: CVE; x_transferred) - http://www.openwall.com/lists/oss-security/2023/10/03/8 (ADP: CVE; x_transferred) - https://access.redhat.com/errata/RHSA-2023:5453 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/errata/RHSA-2023:5455 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/errata/RHSA-2023:7409 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred) - https://access.redhat.com/security/cve/CVE-2023-4806 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred) - https://bugzilla.redhat.com/show_bug.cgi?id=2237782 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4DBUQRRPB47TC3NJOUIBVWUGFHBJAFDL/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DFG4P76UHHZEWQ26FWBXG76N2QLKKPZA/ (ADP: CVE; x_transferred) - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NDAQWHTSVOCOZ5K6KPIWKRT3JX4RTZUR/ (ADP: CVE; x_transferred) - https://security.gentoo.org/glsa/202310-03 (ADP: CVE; x_transferred) - https://security.netapp.com/advisory/ntap-20240125-0008/ (ADP: CVE; x_transferred) - https://cert-portal.siemens.com/productcert/html/ssa-831302.html (ADP: siemens-SADP) - https://cert-portal.siemens.com/productcert/html/ssa-082556.html (ADP: siemens-SADP) ## Provenance - CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-4806; retrieved 2026-11-07; source updated 2026-11-07 - FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-4806; retrieved 2026-11-07; source updated Not reported Revision: 6c47bfd94542d32b2e77223511f3490f9335383f3f09c411a4bf52d25477238f Canonical: https://y2.dev/cve/CVE-2023-4806 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. 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