Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-56391— Out‑of‑bounds Read in GNU coreutils

Quick assessment

Affected
GNU coreutils
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.

GNU coreutils是美国GNU基金会开源的一套基础系统命令行工具集。 GNU coreutils 9.11及之前的9.5.x版本存在缓冲区错误漏洞，该漏洞源于uniq模块在处理-w(–check-chars)选项时对多字节输入处理不当，find_field()函数通过重复处理固定指针而不是推进输入来错误计算字符的字节长度，导致长度值膨胀，此错误长度随后在memcmp操作中使用，导致在处理特制多字节输入时读取超出分配的缓冲区，造成崩溃并可能暴露相邻堆内存。

CVSS 4.6 · Medium EPSS 0.13% · P3

Affected Version Matrix 1

VendorProduct Version RangeStatus
GNU coreutils 9.5≤ 9.11 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-56391

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Out‑of‑bounds Read in GNU coreutils
Source: CVE Program / CVE List V5
Vulnerability Description
GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters by repeatedly processing a fixed pointer instead of advancing through the input, resulting in an inflated length value. This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input. When running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure. This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
跨界内存读
Source: CVE Program / CVE List V5
Vulnerability Title
GNU coreutils 缓冲区错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
GNU coreutils是美国GNU基金会开源的一套基础系统命令行工具集。 GNU coreutils 9.11及之前的9.5.x版本存在缓冲区错误漏洞，该漏洞源于uniq模块在处理-w(–check-chars)选项时对多字节输入处理不当，find_field()函数通过重复处理固定指针而不是推进输入来错误计算字符的字节长度，导致长度值膨胀，此错误长度随后在memcmp操作中使用，导致在处理特制多字节输入时读取超出分配的缓冲区，造成崩溃并可能暴露相邻堆内存。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
GNU coreutils 9.5 ~ 9.11 -

II. Public POCs for CVE-2026-56391

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-56391

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-56391 (2)

Security Blog Posts for CVE-2026-56391 (1)

IV. Related Vulnerabilities

Same product: coreutils
Same vendor: GNU
Same weakness: CWE-125