Glibc: potential use-after-free in getaddrinfo()

Description

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.

Timeline

Scores

EPSS (exploitation in 30 days)

1.6% · top 24% of all CVEs (7 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.

Weakness

• CWE-416: Use After Free (opens in a new tab)All about CWE-416 and its CVEs

Affected products

• Red Hat · Red Hat Enterprise Linux 8

  • unaffected 0:2.28-225.el8_8.6 – < *

• Red Hat · Red Hat Enterprise Linux 8

  • unaffected 0:2.28-225.el8_8.6 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support

  • unaffected 0:2.28-189.8.el8_6 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:2.34-60.el9_2.7 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:2.34-60.el9_2.7 – < *

• Red Hat · Red Hat Virtualization 4 for Red Hat Enterprise Linux 8

  • unaffected 0:2.28-189.8.el8_6 – < *

• Red Hat · Red Hat Enterprise Linux 6

  All versions: unknown

• Red Hat · Red Hat Enterprise Linux 6

  All versions: unknown

• Red Hat · Red Hat Enterprise Linux 7

  All versions: affected

• Red Hat · Red Hat Enterprise Linux 7

  All versions: affected

References (16)

• RHSA-2023:5453 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• RHSA-2023:5455 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• RHSA-2023:7409 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• https://access.redhat.com/security/cve/CVE-2023-4806 (opens in a new tab)vdb-entryx_refsource_REDHATx_transferred
• RHBZ#2237782 (opens in a new tab)issue-trackingx_refsource_REDHATx_transferred
• http://www.openwall.com/lists/oss-security/2023/10/03/4 (opens in a new tab)x_transferred
• http://www.openwall.com/lists/oss-security/2023/10/03/5 (opens in a new tab)x_transferred
• http://www.openwall.com/lists/oss-security/2023/10/03/6 (opens in a new tab)x_transferred
• http://www.openwall.com/lists/oss-security/2023/10/03/8 (opens in a new tab)x_transferred
• https://lists.fedoraproject.org/archives/list/[email protected]/message/4DBUQRRPB47TC3NJOUIBVWUGFHBJAFDL/ (opens in a new tab)x_transferred
• https://lists.fedoraproject.org/archives/list/[email protected]/message/DFG4P76UHHZEWQ26FWBXG76N2QLKKPZA/ (opens in a new tab)x_transferred
• https://lists.fedoraproject.org/archives/list/[email protected]/message/NDAQWHTSVOCOZ5K6KPIWKRT3JX4RTZUR/ (opens in a new tab)x_transferred
• https://security.gentoo.org/glsa/202310-03 (opens in a new tab)x_transferred
• https://security.netapp.com/advisory/ntap-20240125-0008/ (opens in a new tab)x_transferred
• https://cert-portal.siemens.com/productcert/html/ssa-831302.html (opens in a new tab)
• https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-4806](https://trackcve.app/badge/CVE-2023-4806.svg)](https://trackcve.app/cve/CVE-2023-4806)

Record last updated 7 Nov 2026, 11:31 UTC.