RHEL 9 : glibc (RHSA-2026:20597)

medium Nessus Plugin ID 316898

Synopsis

The remote Red Hat host is missing one or more security updates for glibc.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:20597 advisory.

The glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the name service cache daemon (nscd) used by multiple programs on the system.
Without these libraries, the Linux system cannot function correctly.

Security Fix(es):

* glibc: glibc: Incorrect DNS response parsing via crafted DNS server response (CVE-2026-4437)

* glibc: glibc: Invalid DNS hostname returned via gethostbyaddr functions (CVE-2026-4438)

* glibc: glibc: Denial of Service via iconv() function with specific character sets (CVE-2026-4046)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL glibc package based on the guidance in RHSA-2026:20597.

See Also

https://access.redhat.com/security/updates/classification/#moderate

https://bugzilla.redhat.com/show_bug.cgi?id=2449777

https://bugzilla.redhat.com/show_bug.cgi?id=2449783

https://bugzilla.redhat.com/show_bug.cgi?id=2453117

https://issues.redhat.com/browse/RHEL-148252

http://www.nessus.org/u?955ee4d0

https://access.redhat.com/errata/RHSA-2026:20597

Plugin Details

Severity: Medium

ID: 316898

File Name: redhat-RHSA-2026-20597.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 5/27/2026

Updated: 5/27/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

CVSS Score Source: CVE-2026-4437

CVSS v3

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.9

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2026-4438

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:glibc, p-cpe:/a:redhat:enterprise_linux:glibc-common, p-cpe:/a:redhat:enterprise_linux:glibc-devel, p-cpe:/a:redhat:enterprise_linux:glibc-headers, p-cpe:/a:redhat:enterprise_linux:glibc-utils, p-cpe:/a:redhat:enterprise_linux:nscd, p-cpe:/a:redhat:enterprise_linux:glibc-static, p-cpe:/a:redhat:enterprise_linux:glibc-all-langpacks, p-cpe:/a:redhat:enterprise_linux:glibc-benchtests, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-aa, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-af, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-agr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ak, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-am, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-an, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-anp, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ar, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-as, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ast, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ayc, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-az, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-be, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bem, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ber, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bg, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bhb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bho, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-br, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-brx, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-bs, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-byn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ca, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ce, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-chr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-cmn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-crh, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-cs, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-csb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-cv, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-cy, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-da, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-de, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-doi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-dsb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-dv, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-dz, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-el, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-en, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-eo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-es, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-et, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-eu, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fa, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ff, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fil, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fur, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-fy, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ga, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-gd, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-gez, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-gl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-gu, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-gv, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ha, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hak, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-he, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hif, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hne, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hsb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ht, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hu, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-hy, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ia, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-id, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ig, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ik, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-is, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-it, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-iu, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ja, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ka, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kab, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kk, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-km, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ko, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kok, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ks, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ku, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-kw, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ky, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lg, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-li, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lij, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ln, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lt, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lv, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-lzh, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mag, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mai, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mfe, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mg, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mhr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-miq, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mjw, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mk, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ml, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mni, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ms, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mt, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-my, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nan, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nds, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ne, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nhn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-niu, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-nso, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-oc, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-om, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-or, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-os, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-pa, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-pap, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-pl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ps, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-pt, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-quz, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-raj, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ro, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ru, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-rw, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sa, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sah, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sat, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sc, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sd, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-se, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sgs, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-shn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-shs, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-si, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sid, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sk, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sm, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-so, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sq, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ss, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-st, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sv, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-sw, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-szl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ta, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tcy, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-te, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tg, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-th, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-the, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ti, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tig, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tk, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tl, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tn, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-to, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tpi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tr, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ts, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-tt, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ug, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-uk, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-unm, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ur, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-uz, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ve, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-vi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-wa, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-wae, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-wal, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-wo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-xh, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-yi, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-yo, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-yue, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-yuw, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-zh, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-zu, p-cpe:/a:redhat:enterprise_linux:glibc-locale-source, p-cpe:/a:redhat:enterprise_linux:glibc-minimal-langpack, p-cpe:/a:redhat:enterprise_linux:glibc-nss-devel, p-cpe:/a:redhat:enterprise_linux:libnsl, p-cpe:/a:redhat:enterprise_linux:nss_db, p-cpe:/a:redhat:enterprise_linux:nss_hesiod, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:glibc-doc, p-cpe:/a:redhat:enterprise_linux:glibc-gconv-extra, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-ckb, p-cpe:/a:redhat:enterprise_linux:glibc-langpack-mnw, cpe:/o:redhat:rhel_eus:9.8

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 3/20/2026

Reference Information

CVE: CVE-2026-4046, CVE-2026-4437, CVE-2026-4438

CWE: 1286, 617, 838

RHSA: 2026:20597