CVE-2026-77117

SHIFT_JISX0213 decoding may hang on crafted input

Published Sep 15, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
Converting crafted SHIFT_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 SHIFT_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 SHIFT_JISX0213 character set is affected, which is not commonly used. The related defect in the EUC_JISX0213 converter is tracked separately as CVE-2026-80489.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8737-1 GNU C Library vulnerabilities
Ubuntu USN Ubuntu USN USN-8737-2 GNU C Library vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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 emit a buffered code point without consuming further input, leading to persistent retry churn. This can result in a denial of service (DoS) for callers converting untrusted text. Converting crafted SHIFT_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 SHIFT_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 SHIFT_JISX0213 character set is affected, which is not commonly used. The related defect in the EUC_JISX0213 converter is tracked separately as CVE-2026-80489.
Title glibc: Non-progress DoS in SHIFT_JISX0213 -&gt SHIFT_JISX0213 decoding may hang on crafted input
References
Type Values Removed Values Added
First Time appeared Gnu
Gnu glibc
Vendors & Products Gnu
Gnu glibc
Type Values Removed Values Added
Description 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 emit a buffered code point without consuming further input, leading to persistent retry churn. This can result in a denial of service (DoS) for callers converting untrusted text.
Title glibc: Non-progress DoS in SHIFT_JISX0213 -&gt
Weaknesses CWE-835
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Weaknesses

Sources

Status
PUBLISHED
Assigner
glibc
Published
Updated
Sep 15, 2026, 12:26 PM
Reserved
Aug 20, 2026, 12:24 PM
Status
Awaiting Analysis
Published
Sep 15, 2026, 11:17 AM
Modified
Sep 18, 2026, 6:17 PM
Severity
Moderate
Public date
Aug 25, 2026, 8:36 AM