Skip to content
Fencer Intel
medium 6.3

CVE-2026-86805 json

AT_SECURE programs may load attacker-controlled code via $ORIGIN

published last mo. modified last mo. also EUVD-2026-84540

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

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.

Patch / fix

  • The GNU C Library glibc 2.45
  • glibc Debian 14 2.43-7

debian advisories DEBIAN-CVE-2026-86805

  • glibc hummingbird 1 2.43-8.7.hum1
  • libnsl hummingbird 1 2.43-8.7.hum1
  • nss_db hummingbird 1 2.43-8.7.hum1
  • glibc32 hummingbird 1 2.43-8.7.hum1
  • nss_hesiod hummingbird 1 2.43-8.7.hum1
  • glibc-utils hummingbird 1 2.43-8.7.hum1
  • glibc-common hummingbird 1 2.43-8.7.hum1
  • glibc-benchtests hummingbird 1 2.43-8.7.hum1

red hat advisories RHSA-2026:72503

  • glibc Linux Micro 6.1 2.38-slfo.1.1_11.1
  • glibc Linux Micro 6.0 2.38-159998.1.1
  • glibc SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 +1 more 2.38-150600.14.61.1
  • glibc SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +8 more 2.31-150300.109.1
  • glibc SLES 16.0, Linux Micro Extras 6.2, Linux Micro 6.2 +1 more 2.40-160000.7.1
  • glibc SLES 11 SP4 LTSS EXTREME CORE 2.11.3-17.110.58.1
  • glibc SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.22-114.55.1

suse advisories SUSE-SU-2026:24281-1SUSE-SU-2026:24326-1SUSE-SU-2026:4669-1SUSE-SU-2026:4656-1SUSE-SU-2026:4654-1SUSE-SU-2026:4591-1

  • glibc openSUSE Tumbleweed 2.44-3.1
  • glibc openSUSE Leap 16.0 2.40-160000.7.1
  • glibc-cross-s390x-src openSUSE Leap 16.0 2.40-160000.7.1
  • glibc-cross-aarch64-src openSUSE Leap 16.0 2.40-160000.7.1
  • glibc-cross-ppc64le-src openSUSE Leap 16.0 2.40-160000.7.1
  • glibc-cross-riscv64-src openSUSE Leap 16.0 2.40-160000.7.1

opensuse advisories openSUSE-SU-2026:12072-1openSUSE-SU-2026:21968-1

  • glibc AlmaLinux 8 2.28-251.el8_10.53
  • nscd AlmaLinux 8 2.28-251.el8_10.53
  • libnsl AlmaLinux 8 2.28-251.el8_10.53
  • nss_db AlmaLinux 8 2.28-251.el8_10.53
  • nss_hesiod AlmaLinux 8 2.28-251.el8_10.53
  • glibc-utils AlmaLinux 8 2.28-251.el8_10.53
  • glibc-common AlmaLinux 8 2.28-251.el8_10.53
  • glibc-benchtests AlmaLinux 8 2.28-251.el8_10.53

almalinux advisories ALSA-2026:96087ALSA-2026:95618

  • glibc Rocky Linux 8 2.28-251.el8_10.53
  • glibc Rocky Linux 9 2.34-284.el9_8.4

rocky linux advisories RLSA-2026:96087RLSA-2026:95618

Is CVE-2026-86805 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-86805 updated cvss 7.0

glibc: glibc: Privilege escalation and arbitrary code execution via TOCTOU race condition in dynamic loader

  • Red Hat Enterprise Linux 7 nscd, glibc, glibc-utils, glibc-common Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-core-bff-rhel9, rhoai/odh-dashboard-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-mod-arch-automl-rhel9, rhoai/odh-mod-arch-gen-ai-rhel9, rhoai/odh-mod-arch-mlflow-rhel9, +6 more
    under investigation
  • Red Hat Enterprise Linux AppStream (v. 8) glibc-utils 2.28-251.el8_10.53, compat-libpthread-nonshared 2.28-251.el8_10.53
    fixed: vendor fix RHSA-2026:96087
  • Red Hat Enterprise Linux AppStream (v. 9) glibc-utils 2.34-290.el9_9, glibc-utils 2.34-284.el9_8.4, glibc-locale-source 2.34-290.el9_9, glibc-locale-source 2.34-284.el9_8.4
    fixed: vendor fix RHSA-2026:95618
  • Red Hat Enterprise Linux AppStream (v. 10) glibc-utils 2.39-147.el10_3, glibc-locale-source 2.39-147.el10_3
    fixed: vendor fix RHSA-2026:98599
  • Red Hat Enterprise Linux BaseOS (v. 8) nscd 2.28-251.el8_10.53, glibc 2.28-251.el8_10.53, libnsl 2.28-251.el8_10.53, nss_db 2.28-251.el8_10.53, glibc-common 2.28-251.el8_10.53, glibc-gconv-extra 2.28-251.el8_10.53, +3 more
    fixed: vendor fix RHSA-2026:96087
  • Red Hat Enterprise Linux BaseOS (v. 9) nscd 2.34-290.el9_9, glibc 2.34-290.el9_9, libnsl 2.34-290.el9_9, nscd 2.34-284.el9_8.4, glibc 2.34-284.el9_8.4, libnsl 2.34-284.el9_8.4, +8 more
    fixed: vendor fix RHSA-2026:95618
  • Red Hat Enterprise Linux BaseOS (v. 10) glibc 2.39-147.el10_3, libnsl 2.39-147.el10_3, glibc-common 2.39-147.el10_3, glibc-gconv-extra 2.39-147.el10_3, glibc-all-langpacks 2.39-147.el10_3, glibc-minimal-langpack 2.39-147.el10_3
    fixed: vendor fix RHSA-2026:98599
show 5 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) nss_db 2.34-290.el9_9, nss_db 2.34-284.el9_8.4, nss_hesiod 2.34-290.el9_9, nss_hesiod 2.34-284.el9_8.4, glibc-benchtests 2.34-290.el9_9, glibc-benchtests 2.34-284.el9_8.4
    fixed: vendor fix RHSA-2026:95618
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) nss_db 2.39-147.el10_3, nss_hesiod 2.39-147.el10_3, glibc-benchtests 2.39-147.el10_3
    fixed: vendor fix RHSA-2026:98599
  • Red Hat Enterprise Linux CRB (v. 8) nss_hesiod 2.28-251.el8_10.53, glibc-benchtests 2.28-251.el8_10.53
    fixed: vendor fix RHSA-2026:96087
  • Red Hat Hardened Images glibc 2.43-8.7.hum1, libnsl 2.43-8.7.hum1, nss_db 2.43-8.7.hum1, glibc32 2.43-8.7.hum1, nss_hesiod 2.43-8.7.hum1, glibc-utils 2.43-8.7.hum1, +9 more
    fixed: vendor fix RHSA-2026:72503
  • Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, compat-glibc, glibc-common Red Hat Enterprise Linux 7 compat-glibc Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-kube-rbac-proxy-rhel9, rhoai/odh-maas-controller-rhel9, rhoai/odh-mlflow-operator-rhel9, rhoai/odh-model-controller-rhel9, rhoai/odh-ogx-k8s-operator-rhel9, +14 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 6.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:L

Affected products

  • The GNU C Library glibc

Classification

Weakness
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.