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TI-2026-03849 Aliases CVE-2026-4438GHSA-935r-rfch-9mr7

gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames

Priority LOW 24CWE-20Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
Low · Low · None
Fix status
Partial Red Hat: 14 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-88.

Summary

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 result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00314 24th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 16 advisoriesRed Hat: 14 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GNUglibc2.34 – 2.43—No fix listedCNA
  • glibc VendorGNU Affected 2.34 – 2.43 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*2.34 – 2.43VulnerableGNU
  • cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* Versions 2.34 – 2.43 Vulnerable ·GNU

Remediation

Red Hat 16 advisories

  • RHSA-2026:82888 Released 2026-10-14 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-bundle
  • RHSA-2026:82857 Released 2026-10-14 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-bundle
  • RHSA-2026:82372 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
Show 13 more Red Hat advisories
  • RHSA-2026:82354 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
  • RHSA-2026:82347 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
  • RHSA-2026:82322 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
  • RHSA-2026:82304 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
  • RHSA-2026:72502 Released 2026-09-28 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.20.1
    • Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-trust-manager-rhel9
  • RHSA-2026:58981 Released 2026-08-24 · Red Hat rating Critical
    Red Hat Update Infrastructure 5.3 Technology Preview security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-tp-rhel9, registry.redhat.io/rhui5/installer-tp-rhel9, registry.redhat.io/rhui5/rhua-tp-rhel9
  • RHSA-2026:29197 Released 2026-06-24 · Red Hat rating Important
    A Subscription Management tool for finding and reporting Red Hat product usage
    • Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
  • RHSA-2026:27998 Released 2026-06-22 · Red Hat rating Important
    Cost Management Metrics Operator Update
    • Cost Management 4 registry.redhat.io/costmanagement/costmanagement-metrics-rhel9-operator
  • RHSA-2026:26319 Released 2026-06-16 · Red Hat rating Important
    Red Hat Update Infrastructure 5.2 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9, registry.redhat.io/rhui5/installer-rhel9 +1
  • RHSA-2026:22634 Released 2026-06-02 · Red Hat rating Important
    Insights proxy Container Image
    • Red Hat Insights proxy 1.5 registry.redhat.io/insights-proxy/insights-proxy-container-rhel9
  • RHSA-2026:20597 Released 2026-05-26 · Red Hat rating Moderate
    glibc security update
    • Red Hat Enterprise Linux AppStream (v. 9) glibc-devel-2.34-270.el9_8, glibc-doc-2.34-270.el9_8, glibc-headers-2.34-270.el9_8 +2
    • Red Hat Enterprise Linux BaseOS (v. 9) glibc-2.34-270.el9_8, glibc-all-langpacks-2.34-270.el9_8, glibc-common-2.34-270.el9_8 +47
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) glibc-benchtests-2.34-270.el9_8, glibc-nss-devel-2.34-270.el9_8, glibc-static-2.34-270.el9_8 +2
  • RHSA-2026:19061 Released 2026-05-19 · Red Hat rating Moderate
    glibc security update
    • Red Hat Enterprise Linux AppStream (v. 10) glibc-devel-2.39-121.el10_2, glibc-doc-2.39-121.el10_2, glibc-locale-source-2.39-121.el10_2 +1
    • Red Hat Enterprise Linux BaseOS (v. 10) glibc-2.39-121.el10_2, glibc-all-langpacks-2.39-121.el10_2, glibc-common-2.39-121.el10_2 +47
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) glibc-benchtests-2.39-121.el10_2, glibc-nss-devel-2.39-121.el10_2, glibc-static-2.39-121.el10_2 +2
  • RHSA-2026:7316 Released 2026-04-09 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images glibc-2.42-11.1.hum1@aarch64, glibc-2.42-11.1.hum1@src, glibc-2.42-11.1.hum1@x86_64 +47

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Cert Manager support for Red Hat OpenShift release 1.17Fixed RHSA-2026:82304, RHSA-2026:82322, RHSA-2026:82888
Cert Manager support for Red Hat OpenShift release 1.18Fixed RHSA-2026:82347, RHSA-2026:82354, RHSA-2026:82372, RHSA-2026:82857
Cert Manager support for Red Hat OpenShift release 1.20Fixed RHSA-2026:72502
Cost Management 4Fixed RHSA-2026:27998
Red Hat Discovery 2Fixed RHSA-2026:29197
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:19061
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:20597
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:19061
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:20597
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:19061
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:20597
Red Hat Hardened ImagesFixed RHSA-2026:7316
Red Hat Insights proxy 1.5Fixed RHSA-2026:22634
Red Hat Update Infrastructure 5Fixed RHSA-2026:26319, RHSA-2026:58981
Not affected: 3 products
  • Cost Management 4
  • Red Hat Hardened Images
  • Red Hat Update Infrastructure 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-4438
  2. 2026-10-03 Alias added: GHSA-935r-rfch-9mr7
  3. 2026-10-14 Fix available: RHSA-2026:82304 · Red Hat
  4. 2026-10-14 Fix available: RHSA-2026:82322 · Red Hat
  5. 2026-10-14 Fix available: RHSA-2026:82372 · Red Hat
  6. 2026-10-14 Fix available: RHSA-2026:82354 · Red Hat
  7. 2026-10-14 Fix available: RHSA-2026:82347 · Red Hat
  8. 2026-10-15 Fix available: RHSA-2026:82857 · Red Hat
  9. 2026-10-15 Fix available: RHSA-2026:82888 · Red Hat
  10. 2026-10-16 Fix available: Cert Manager support for Red Hat OpenShift release 1.17, Cert Manager support for Red Hat OpenShift release 1.18 · Red Hat

References

Exploit 1

  • TI-2023-04522 Glibc: buffer overflow in ld.so leading to privilege escalation KEVCVSS 3.1HIGH 7.8
  • TI-2015-00205 Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and… CVSS 2.0HIGH 10.0
  • TI-2026-04772 scanf %mc off-by-one heap buffer overflow CVSS 3.1CRITICAL 9.8
  • TI-2022-07360 The deprecated compatibility function clnt_create in the sunrpc module of the GNU C… CVSS 3.1CRITICAL 9.8
  • TI-2022-07359 The deprecated compatibility function svcunix_create in the sunrpc module of the GNU C… CVSS 3.1CRITICAL 9.8
  • TI-2015-06274 Multiple stack-based buffer overflows in the (1) send_dg and (2) send_vc functions in the… CVSS 3.0HIGH 8.1
See all 162 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences