Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-27T08:49:17 glibc: Non-progress DoS in EUC_JISX0213 -> UCS-4 conversion state 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-835

Converting crafted EUC_JISX0213 input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.3 to 2.44 may result in the converter making no progress, causing the calling application to hang. Some EUC_JISX0213 sequences decode to two code points. If the output buffer has room for only the first one, the converter stores the second in the conversion state and returns E2BIG, but it never clears that pending character after emitting it on the next call. The converter then keeps emitting the pending character without consuming further input, so an application that retries the conversion loops forever. The input must be attacker controlled and the application must convert it with an output buffer small enough to split the two code points. Only the EUC_JISX0213 character set is affected, which is not commonly used. The related defect in SHIFT_JISX0213 converter is tracked separately as CVE-2026-77117.

A flaw was found in glibc. A remote attacker could exploit this vulnerability by providing specially crafted input during SHIFT_JISX0213 to UCS-4 text conversion. This crafted input can cause the application to repeatedly process a buffered character without consuming further input, leading to a persistent loop and a denial of service (DoS) condition. This could make the affected application unresponsive.

This Moderate flaw in glibc's SHIFT_JISX0213 to UCS-4 conversion can lead to a denial of service. The attack surface is significantly limited as exploitation requires applications to process untrusted input via this specific conversion path, trigger a precise 2-byte sequence, and then repeatedly attempt conversion after an E2BIG error with insufficient output space. This combination of uncommon application behaviors makes widespread impact less likely. This issue was discovered by Found by AISLE in partnership with Red Hat (Aisle Research). Red Hat Hardened Images 2026-08-31T00:00:00Z RHSA-2026:61737 glibc-main-2.43-8.4.hum1 Red Hat Enterprise Linux 10 Affected glibc Red Hat Enterprise Linux 6 Under investigation compat-glibc Red Hat Enterprise Linux 6 Under investigation glibc Red Hat Enterprise Linux 7 Under investigation compat-glibc Red Hat Enterprise Linux 7 Under investigation glibc Red Hat Enterprise Linux 8 Under investigation glibc Red Hat Enterprise Linux 9 Affected glibc Red Hat OpenShift Container Platform 4 Under investigation openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Under investigation openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-80489 https://nvd.nist.gov/vuln/detail/CVE-2026-80489