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Fencer Vulns
high 7.0

CVE-2026-84243 json

gettext: Directory traversal via the LANGUAGE environment variable

published 2026-10-30 9 d ago modified 2026-10-31 9 d ago also EUVD-2026-114247

cvss
7.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

The gettext family of functions in the GNU C Library version 2.0 and later accept LANGUAGE environment variable entries that contain '/' or that are equal to "..", unless the program is setuid or setgid (AT_SECURE). An attacker who can set LANGUAGE in the environment of a program that uses gettext can make it load a message catalog (.mo file) from an arbitrary location in the file system. A crafted .mo file can crash the program through out-of-range offsets, or supply translations whose format directives do not match the arguments passed by the program. That causes undefined behaviour in the printf family of functions and may allow arbitrary code execution with the privileges of the program. The safety of message catalogs relies on them being installed in trusted, read-only locations, and the directory traversal bypasses this.

The fix for CVE-2014-0475 rejects ".." path components in locale names passed to setlocale or taken from the LC_ALL, LC_* and LANG environment variables. gettext reads LANGUAGE directly and appends each colon-separated entry to the message catalog directory, so that fix did not cover LANGUAGE.

LANGUAGE is only used when the LC_MESSAGES locale is not "C", "C.<encoding>" or "POSIX", so the attacker must also be able to select another installed locale, for example through LANG or LC_ALL. Exploitation also requires that the attacker can place the crafted file in a location readable by the target program, and that the environment crosses a trust boundary without the program running as AT_SECURE. An example is an SSH server that accepts LANGUAGE and LANG from clients through the AcceptEnv directive and restricts an account to a forced command; the attacker may use this to escape the restriction.

Patch / fix

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-2026-84243 updated cvss 7.0

glibc: glibc: Arbitrary code execution via directory traversal in LANGUAGE environment variable

  • Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, glibc-common, compat-glibc 2.5-46.2, glibc 2.39-145.el10_2
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 nscd, glibc, glibc-utils, compat-glibc, glibc-common, compat-glibc 2.5-46.2, +1 more Red Hat Enterprise Linux 8 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +8 more Red Hat Enterprise Linux 9 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +7 more Red Hat Enterprise Linux 10 glibc 2.39-145.el10_2 Red Hat Hardened Images glibc 2.39-145.el10_2 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, 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 Hardened Images filesystem 3.18-59.1.hum1 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
10 d ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • The GNU C Library glibc

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

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