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Fencer Intel
medium 5.9

CVE-2026-122054 json

BIG-HKSCS decoding hang on crafted input

published 5d ago modified 5h ago also EUVD-2026-117002

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

Converting crafted BIG-HKSCS input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.18 through 2.31 may result in the converter making no progress, causing the calling application to hang.

Patch / fix

  • glibc Debian 14, Debian 13, Debian 12 2.32-1

debian advisories DEBIAN-CVE-2026-122054

Is CVE-2026-122054 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.

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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-2026-122054 updated cvss 5.9

glibc: glibc: Denial of Service via crafted BIG-HKSCS input conversion

  • Red Hat Hardened Images glibc 2.39-145.el10_2, filesystem 3.18-59.1.hum1
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, glibc-common, compat-glibc 2.5-46.2, glibc 2.39-145.el10_2 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 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
    under investigation

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
partial
Assessed
5h ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • The GNU C Library glibc

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit 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.