CVE-2026-122054— BIG-HKSCS decoding hang on crafted input

Quick assessment

Affected

The GNU C Library glibc

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 GNU C 库（glibc）2.18 至 2.31 版本中，若使用等工具将特制的 BIG-HKSCS 输入转换为 UCS-4 或内部宽字符编码，可能导致转换器无法推进，进而使调用该转换器的应用程序陷入挂起状态。

CVSS 5.9 · Medium Updated Nov 05, 2026

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

Vendor	Product	Version Range	Status
The GNU C Library	glibc	`2.18≤ 2.31`	affected

Get alerts for future matching vulnerabilities Log in to subscribe

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!

View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title

BIG-HKSCS decoding hang on crafted input

Source: CVE Program / CVE List V5

Vulnerability Description

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.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

不可达退出条件的循环(无限循环)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
The GNU C Library	glibc	2.18 ~ 2.31	-

II. Public POCs for CVE-2026-122054

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-122054

请登录查看更多情报信息。

Other References for CVE-2026-122054 (2)

https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0026 vendor-advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=25734 issue-tracking

https://www.cve.org/CVERecord?id=CVE-2026-122054

IV. Related Vulnerabilities

Same product: glibc

Same vendor: The GNU C Library

Same weakness: CWE-835