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Vulnerabilities

Vulnerability · CVE-2026-84243

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 progr

Published Oct 30, 2026 · catalog updated Oct 31, 2026 · Red Hat Red Hat Enterprise Linux

Last checked Oct 31, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-84243. EPSS is 0.30%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.30%
Remediation
Advisory link
Affected products
Debian:12 glibc · Debian:13 glibc · Debian:14 glibc

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. " 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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 glibc2.36-10~0, 2.36-9, 2.36-9+deb12u1
  • Debian:13 glibc2.41-12, 2.41-12+deb13u1, 2.41-12+deb13u2
  • Debian:14 glibc2.41-12, 2.41-13~hurd.0, 2.41-13~hurd.1

How to fix CVE-2026-84243

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-84243. EPSS is 0.30%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Which versions are affected?

Compare what you have installed with 2.36-10~0, 2.36-9, 2.36-9+deb12u1, 2.41-12, 2.41-12+deb13u1, 2.41-12+deb13u2, 2.41-12, 2.41-13~hurd.0, 2.41-13~hurd.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-22: Path Traversal. EPSS 0.30%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 30, 2026 · OpenSSF OSV / OSV Scanner

    Detected

  2. Oct 31, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    The description or metadata changed.

  3. Oct 31, 2026 · Trivy Vulnerability DB

    Updated

    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 crafte

Sources

  • CVE.orgVulnerability recordCVE-2026-84243

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-84243

    30-day exploitation probability 0.30%

    first.org
  • OpenCVEVendor advisoryCVE-2026-84243

    CVE-2026-84243 is named on the public OpenCVE page.

    opencve.io
  • OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-84243
    osv.dev
  • Red Hat Security DataVendor advisoryCVE-2026-84243

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

    access.redhat.com
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-84243

    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

    osv.dev

References

Freshness

Last verified in this catalog Oct 31, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 31, 2026
  • CVE.orgOct 31, 2026
  • Trivy Vulnerability DBOct 31, 2026
  • Red Hat Security DataOct 31, 2026
  • OpenCVEOct 31, 2026
  • OpenSSF OSV / OSV ScannerOct 31, 2026