Amazon Linux 2023 : compat-libpthread-nonshared, glibc, glibc-all-langpacks (ALAS2023-2026-3396)

medium Nessus Plugin ID 377911

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-3396 advisory.

A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DT_RPATH for setuid/setgid (AT_SECURE) programs, glibc validates the lexically normalized search path against the trusted directories but then opens the raw, un-normalized path. On systems where the Linux fs.protected_hardlinks sysctl is disabled, a local attacker who hard-links such a program into an attacker-controlled directory and wins a race to replace an intermediate path component with a symbolic link can direct the loader outside the trusted directory, causing it to load an attacker-controlled shared object and execute arbitrary code with the elevated privileges of the program.

Exploitation requires an installed setuid or setgid binary whose DT_RPATH uses $ORIGIN followed by ..
traversal that normalizes into a trusted directory, and the ability to hard-link that binary and win the race by swapping a path component for a symbolic link. Major Linux-based OS distributions ship with fs.protected_hardlinks enabled by default and mitigate the vulnerability. (CVE-2026-86805)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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

Solution

Run 'dnf update glibc --releasever 2023.12.20261109' or or 'dnf update --advisory ALAS2023-2026-3396 --releasever 2023.12.20261109' to update your system.

See Also

https://alas.aws.amazon.com//AL2023/ALAS2023-2026-3396.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-86805.html

Plugin Details

Severity: Medium

ID: 377911

File Name: al2023_ALAS2023-2026-3396.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 11/9/2026

Updated: 11/9/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.5

Percentile: 57.76

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.4

Vector: CVSS2#AV:L/AC:H/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-86805

CVSS v3

Risk Factor: Medium

Base Score: 6.3

Temporal Score: 5.5

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:compat-libpthread-nonshared, p-cpe:/a:amazon:linux:glibc-all-langpacks, p-cpe:/a:amazon:linux:glibc-benchtests-debuginfo, p-cpe:/a:amazon:linux:glibc-benchtests, p-cpe:/a:amazon:linux:glibc-common-debuginfo, p-cpe:/a:amazon:linux:glibc-common, p-cpe:/a:amazon:linux:glibc-debuginfo, p-cpe:/a:amazon:linux:glibc-debugsource, p-cpe:/a:amazon:linux:glibc-devel, p-cpe:/a:amazon:linux:glibc-doc, p-cpe:/a:amazon:linux:glibc-gconv-extra-debuginfo, p-cpe:/a:amazon:linux:glibc-gconv-extra, p-cpe:/a:amazon:linux:glibc-headers-x86, p-cpe:/a:amazon:linux:glibc-langpack-aa, p-cpe:/a:amazon:linux:glibc-langpack-af, p-cpe:/a:amazon:linux:glibc-langpack-agr, p-cpe:/a:amazon:linux:glibc-langpack-ak, p-cpe:/a:amazon:linux:glibc-langpack-am, p-cpe:/a:amazon:linux:glibc-langpack-an, p-cpe:/a:amazon:linux:glibc-langpack-anp, p-cpe:/a:amazon:linux:glibc-langpack-ar, p-cpe:/a:amazon:linux:glibc-langpack-as, p-cpe:/a:amazon:linux:glibc-langpack-ast, p-cpe:/a:amazon:linux:glibc-langpack-ayc, p-cpe:/a:amazon:linux:glibc-langpack-az, p-cpe:/a:amazon:linux:glibc-langpack-be, p-cpe:/a:amazon:linux:glibc-langpack-bem, p-cpe:/a:amazon:linux:glibc-langpack-ber, p-cpe:/a:amazon:linux:glibc-langpack-bg, p-cpe:/a:amazon:linux:glibc-langpack-bhb, p-cpe:/a:amazon:linux:glibc-langpack-bho, p-cpe:/a:amazon:linux:glibc-langpack-bi, p-cpe:/a:amazon:linux:glibc-langpack-bn, p-cpe:/a:amazon:linux:glibc-langpack-bo, p-cpe:/a:amazon:linux:glibc-langpack-br, p-cpe:/a:amazon:linux:glibc-langpack-brx, p-cpe:/a:amazon:linux:glibc-langpack-bs, p-cpe:/a:amazon:linux:glibc-langpack-byn, p-cpe:/a:amazon:linux:glibc-langpack-ca, p-cpe:/a:amazon:linux:glibc-langpack-ce, p-cpe:/a:amazon:linux:glibc-langpack-chr, p-cpe:/a:amazon:linux:glibc-langpack-ckb, p-cpe:/a:amazon:linux:glibc-langpack-cmn, p-cpe:/a:amazon:linux:glibc-langpack-crh, p-cpe:/a:amazon:linux:glibc-langpack-cs, p-cpe:/a:amazon:linux:glibc-langpack-csb, p-cpe:/a:amazon:linux:glibc-langpack-cv, p-cpe:/a:amazon:linux:glibc-langpack-cy, p-cpe:/a:amazon:linux:glibc-langpack-da, p-cpe:/a:amazon:linux:glibc-langpack-de, p-cpe:/a:amazon:linux:glibc-langpack-doi, p-cpe:/a:amazon:linux:glibc-langpack-dsb, p-cpe:/a:amazon:linux:glibc-langpack-dv, p-cpe:/a:amazon:linux:glibc-langpack-dz, p-cpe:/a:amazon:linux:glibc-langpack-el, p-cpe:/a:amazon:linux:glibc-langpack-en, p-cpe:/a:amazon:linux:glibc-langpack-eo, p-cpe:/a:amazon:linux:glibc-langpack-es, p-cpe:/a:amazon:linux:glibc-langpack-et, p-cpe:/a:amazon:linux:glibc-langpack-eu, p-cpe:/a:amazon:linux:glibc-langpack-fa, p-cpe:/a:amazon:linux:glibc-langpack-ff, p-cpe:/a:amazon:linux:glibc-langpack-fi, p-cpe:/a:amazon:linux:glibc-langpack-fil, p-cpe:/a:amazon:linux:glibc-langpack-fo, p-cpe:/a:amazon:linux:glibc-langpack-fr, p-cpe:/a:amazon:linux:glibc-langpack-fur, p-cpe:/a:amazon:linux:glibc-langpack-fy, p-cpe:/a:amazon:linux:glibc-langpack-ga, p-cpe:/a:amazon:linux:glibc-langpack-gd, p-cpe:/a:amazon:linux:glibc-langpack-gez, p-cpe:/a:amazon:linux:glibc-langpack-gl, p-cpe:/a:amazon:linux:glibc-langpack-gu, p-cpe:/a:amazon:linux:glibc-langpack-gv, p-cpe:/a:amazon:linux:glibc-langpack-ha, p-cpe:/a:amazon:linux:glibc-langpack-hak, p-cpe:/a:amazon:linux:glibc-langpack-he, p-cpe:/a:amazon:linux:glibc-langpack-hi, p-cpe:/a:amazon:linux:glibc-langpack-hif, p-cpe:/a:amazon:linux:glibc-langpack-hne, p-cpe:/a:amazon:linux:glibc-langpack-hr, p-cpe:/a:amazon:linux:glibc-langpack-hsb, p-cpe:/a:amazon:linux:glibc-langpack-ht, p-cpe:/a:amazon:linux:glibc-langpack-hu, p-cpe:/a:amazon:linux:glibc-langpack-hy, p-cpe:/a:amazon:linux:glibc-langpack-ia, p-cpe:/a:amazon:linux:glibc-langpack-id, p-cpe:/a:amazon:linux:glibc-langpack-ig, p-cpe:/a:amazon:linux:glibc-langpack-ik, p-cpe:/a:amazon:linux:glibc-langpack-is, p-cpe:/a:amazon:linux:glibc-langpack-it, p-cpe:/a:amazon:linux:glibc-langpack-iu, p-cpe:/a:amazon:linux:glibc-langpack-ja, p-cpe:/a:amazon:linux:glibc-langpack-ka, p-cpe:/a:amazon:linux:glibc-langpack-kab, p-cpe:/a:amazon:linux:glibc-langpack-kk, p-cpe:/a:amazon:linux:glibc-langpack-kl, p-cpe:/a:amazon:linux:glibc-langpack-km, p-cpe:/a:amazon:linux:glibc-langpack-kn, p-cpe:/a:amazon:linux:glibc-langpack-ko, p-cpe:/a:amazon:linux:glibc-langpack-kok, p-cpe:/a:amazon:linux:glibc-langpack-ks, p-cpe:/a:amazon:linux:glibc-langpack-ku, p-cpe:/a:amazon:linux:glibc-langpack-kw, p-cpe:/a:amazon:linux:glibc-langpack-ky, p-cpe:/a:amazon:linux:glibc-langpack-lb, p-cpe:/a:amazon:linux:glibc-langpack-lg, p-cpe:/a:amazon:linux:glibc-langpack-li, p-cpe:/a:amazon:linux:glibc-langpack-lij, p-cpe:/a:amazon:linux:glibc-langpack-ln, p-cpe:/a:amazon:linux:glibc-langpack-lo, p-cpe:/a:amazon:linux:glibc-langpack-lt, p-cpe:/a:amazon:linux:glibc-langpack-lv, p-cpe:/a:amazon:linux:glibc-langpack-lzh, p-cpe:/a:amazon:linux:glibc-langpack-mag, p-cpe:/a:amazon:linux:glibc-langpack-mai, p-cpe:/a:amazon:linux:glibc-langpack-mfe, p-cpe:/a:amazon:linux:glibc-langpack-mg, p-cpe:/a:amazon:linux:glibc-langpack-mhr, p-cpe:/a:amazon:linux:glibc-langpack-mi, p-cpe:/a:amazon:linux:glibc-langpack-miq, p-cpe:/a:amazon:linux:glibc-langpack-mjw, p-cpe:/a:amazon:linux:glibc-langpack-mk, p-cpe:/a:amazon:linux:glibc-langpack-ml, p-cpe:/a:amazon:linux:glibc-langpack-mn, p-cpe:/a:amazon:linux:glibc-langpack-mni, p-cpe:/a:amazon:linux:glibc-langpack-mnw, p-cpe:/a:amazon:linux:glibc-langpack-mr, p-cpe:/a:amazon:linux:glibc-langpack-ms, p-cpe:/a:amazon:linux:glibc-langpack-mt, p-cpe:/a:amazon:linux:glibc-langpack-my, p-cpe:/a:amazon:linux:glibc-langpack-nan, p-cpe:/a:amazon:linux:glibc-langpack-nb, p-cpe:/a:amazon:linux:glibc-langpack-nds, p-cpe:/a:amazon:linux:glibc-langpack-ne, p-cpe:/a:amazon:linux:glibc-langpack-nhn, p-cpe:/a:amazon:linux:glibc-langpack-niu, p-cpe:/a:amazon:linux:glibc-langpack-nl, p-cpe:/a:amazon:linux:glibc-langpack-nn, p-cpe:/a:amazon:linux:glibc-langpack-nr, p-cpe:/a:amazon:linux:glibc-langpack-nso, p-cpe:/a:amazon:linux:glibc-langpack-oc, p-cpe:/a:amazon:linux:glibc-langpack-om, p-cpe:/a:amazon:linux:glibc-langpack-or, p-cpe:/a:amazon:linux:glibc-langpack-os, p-cpe:/a:amazon:linux:glibc-langpack-pa, p-cpe:/a:amazon:linux:glibc-langpack-pap, p-cpe:/a:amazon:linux:glibc-langpack-pl, p-cpe:/a:amazon:linux:glibc-langpack-ps, p-cpe:/a:amazon:linux:glibc-langpack-pt, p-cpe:/a:amazon:linux:glibc-langpack-quz, p-cpe:/a:amazon:linux:glibc-langpack-raj, p-cpe:/a:amazon:linux:glibc-langpack-ro, p-cpe:/a:amazon:linux:glibc-langpack-ru, p-cpe:/a:amazon:linux:glibc-langpack-rw, p-cpe:/a:amazon:linux:glibc-langpack-sa, p-cpe:/a:amazon:linux:glibc-langpack-sah, p-cpe:/a:amazon:linux:glibc-langpack-sat, p-cpe:/a:amazon:linux:glibc-langpack-sc, p-cpe:/a:amazon:linux:glibc-langpack-sd, p-cpe:/a:amazon:linux:glibc-langpack-se, p-cpe:/a:amazon:linux:glibc-langpack-sgs, p-cpe:/a:amazon:linux:glibc-langpack-shn, p-cpe:/a:amazon:linux:glibc-langpack-shs, p-cpe:/a:amazon:linux:glibc-langpack-si, p-cpe:/a:amazon:linux:glibc-langpack-sid, p-cpe:/a:amazon:linux:glibc-langpack-sk, p-cpe:/a:amazon:linux:glibc-langpack-sl, p-cpe:/a:amazon:linux:glibc-langpack-sm, p-cpe:/a:amazon:linux:glibc-langpack-so, p-cpe:/a:amazon:linux:glibc-langpack-sq, p-cpe:/a:amazon:linux:glibc-langpack-sr, p-cpe:/a:amazon:linux:glibc-langpack-ss, p-cpe:/a:amazon:linux:glibc-langpack-st, p-cpe:/a:amazon:linux:glibc-langpack-sv, p-cpe:/a:amazon:linux:glibc-langpack-sw, p-cpe:/a:amazon:linux:glibc-langpack-szl, p-cpe:/a:amazon:linux:glibc-langpack-ta, p-cpe:/a:amazon:linux:glibc-langpack-tcy, p-cpe:/a:amazon:linux:glibc-langpack-te, p-cpe:/a:amazon:linux:glibc-langpack-tg, p-cpe:/a:amazon:linux:glibc-langpack-th, p-cpe:/a:amazon:linux:glibc-langpack-the, p-cpe:/a:amazon:linux:glibc-langpack-ti, p-cpe:/a:amazon:linux:glibc-langpack-tig, p-cpe:/a:amazon:linux:glibc-langpack-tk, p-cpe:/a:amazon:linux:glibc-langpack-tl, p-cpe:/a:amazon:linux:glibc-langpack-tn, p-cpe:/a:amazon:linux:glibc-langpack-to, p-cpe:/a:amazon:linux:glibc-langpack-tpi, p-cpe:/a:amazon:linux:glibc-langpack-tr, p-cpe:/a:amazon:linux:glibc-langpack-ts, p-cpe:/a:amazon:linux:glibc-langpack-tt, p-cpe:/a:amazon:linux:glibc-langpack-ug, p-cpe:/a:amazon:linux:glibc-langpack-uk, p-cpe:/a:amazon:linux:glibc-langpack-unm, p-cpe:/a:amazon:linux:glibc-langpack-ur, p-cpe:/a:amazon:linux:glibc-langpack-uz, p-cpe:/a:amazon:linux:glibc-langpack-ve, p-cpe:/a:amazon:linux:glibc-langpack-vi, p-cpe:/a:amazon:linux:glibc-langpack-wa, p-cpe:/a:amazon:linux:glibc-langpack-wae, p-cpe:/a:amazon:linux:glibc-langpack-wal, p-cpe:/a:amazon:linux:glibc-langpack-wo, p-cpe:/a:amazon:linux:glibc-langpack-xh, p-cpe:/a:amazon:linux:glibc-langpack-yi, p-cpe:/a:amazon:linux:glibc-langpack-yo, p-cpe:/a:amazon:linux:glibc-langpack-yue, p-cpe:/a:amazon:linux:glibc-langpack-yuw, p-cpe:/a:amazon:linux:glibc-langpack-zh, p-cpe:/a:amazon:linux:glibc-langpack-zu, p-cpe:/a:amazon:linux:glibc-locale-source, p-cpe:/a:amazon:linux:glibc-minimal-langpack, p-cpe:/a:amazon:linux:glibc-nss-devel, p-cpe:/a:amazon:linux:glibc-static, p-cpe:/a:amazon:linux:glibc-utils-debuginfo, p-cpe:/a:amazon:linux:glibc-utils, p-cpe:/a:amazon:linux:glibc, p-cpe:/a:amazon:linux:libnsl-debuginfo, p-cpe:/a:amazon:linux:libnsl, p-cpe:/a:amazon:linux:nscd-debuginfo, p-cpe:/a:amazon:linux:nscd, p-cpe:/a:amazon:linux:nss_db-debuginfo, p-cpe:/a:amazon:linux:nss_db, p-cpe:/a:amazon:linux:nss_hesiod-debuginfo, p-cpe:/a:amazon:linux:nss_hesiod, p-cpe:/a:amazon:linux:sysroot-aarch64-fc34-glibc, p-cpe:/a:amazon:linux:sysroot-x86_64-fc34-glibc

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/9/2026

Vulnerability Publication Date: 9/22/2026

Reference Information

CVE: CVE-2026-86805