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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-54576— mport package installation has symlink TOCTOU in chown and chmod handling

Quick assessment

Affected
MidnightBSD mport
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.

这段文字描述的是 mport（MidnightBSD 包管理器）的一个安全漏洞。以下是翻译： mport 是 MidnightBSD 的包管理器。在 2.7.8 版本之前， 文件中的 函数在安装软件包文件时，使用了基于路径的 、 、 和 操作。拥有目标目录写权限的本地攻击者可以在应用特权所有权或模式更改之前，将已检查的文件替换为符号链接（symlink），从而将这些更改重定向到攻击者指定的路径，进而破坏文件系统完整性或权限设置。该问题已在 2.7.8 版本中修复。

CVSS 5.8 · Medium

Possible ATT&CK Techniques 1 AI

T1554.001
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-54576

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
mport package installation has symlink TOCTOU in chown and chmod handling
Source: CVE Program / CVE List V5
Vulnerability Description
mport is the MidnightBSD Package Manager. Prior to 2.7.8, do_actual_install() in libmport/bundle_read_install_pkg.c used path-based lstat(), chown(), stat(), and chmod() operations while installing package files. A local attacker with write access to a target directory could replace a checked file with a symlink before privileged ownership or mode changes were applied, redirecting those changes to an attacker-selected path and compromising filesystem integrity or permissions. This issue is fixed in version 2.7.8.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
在文件访问前对链接解析不恰当(链接跟随)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
MidnightBSD mport < 2.7.8 -

II. Public POCs for CVE-2026-54576

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-54576

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-54576 (2)

Vendor Advisories for CVE-2026-54576 (1)

Other References for CVE-2026-54576 (1)

Same Patch Batch · MidnightBSD · 2026-09-17 · 12 CVEs total

CVE-2026-54583 8.3 HIGH mport package bundle downloads allow unsafe destination filenames
CVE-2026-54581 8.3 HIGH mport bootstrap index fetch can continue after hash verification failure
CVE-2026-54580 8.3 HIGH mport index decompression can leave partial or corrupt index data after zstd failures
CVE-2026-54582 6.0 MEDIUM mport package installation can overwrite existing unmanaged or differently owned files
CVE-2026-54585 6.0 MEDIUM mport sample file handling can write outside the configured root
CVE-2026-54586 6.0 MEDIUM mport permits repository and package mirror fetches over insecure transport
CVE-2026-54587 5.8 MEDIUM mport directory asset installation is vulnerable to symlink and path traversal races
CVE-2026-54575 5.8 MEDIUM mport package fetch and clean paths are vulnerable to TOCTOU filesystem races
CVE-2026-54579 2.3 LOW mport mirror-selection ping accepts insufficiently validated ICMP replies
CVE-2026-54577 2.0 LOW mport audit can inspect the wrong package when options are present
CVE-2026-54578 2.0 LOW mport verify can compare stale checksum data after hashing failures

IV. Related Vulnerabilities

Same product: mport
Same vendor: MidnightBSD
Same weakness: CWE-59

V. Comments for CVE-2026-54576

No comments yet

Leave a comment