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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-64846— Nix: Arbitrary file truncation outside the sandbox with recursive-nix experimental feature

Quick assessment

Affected
NixOS nix
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.

Nix 是用于 Linux 及其他 Unix 系统的包管理器。在版本 2.35.0 之前，若启用 实验性功能并执行恶意的构建推导（derivation），则可能在 LocalStore 恢复路径中利用最终符号链接处理方面的“检查时/使用时”（Time-of-Check/Time-of-Use, TOCTOU）竞争条件。该竞争条件可导致 在打开带有 标志的路径时，跟随被替换的最终符号链接，而非强制执行 策略。由此，Nix 进程或 可能以守护进程用户的权限，在构建沙箱外部创建或截断空文件。该漏洞原语不支持任意内容写入，

CVSS 2.8 · Low EPSS 0.09% · P0

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 1

VendorProduct Version RangeStatus
NixOS nix < 2.35.0 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-64846

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Nix: Arbitrary file truncation outside the sandbox with recursive-nix experimental feature
Source: CVE Program / CVE List V5
Vulnerability Description
Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
CWE-61
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
NixOS nix < 2.35.0 -

II. Public POCs for CVE-2026-64846

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-64846

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-64846 (2)

Vendor Advisories for CVE-2026-64846 (1)

IV. Related Vulnerabilities

Same product: nix
Same vendor: NixOS
Same weakness: CWE-61

V. Comments for CVE-2026-64846

No comments yet

Leave a comment