CVE-2026-105840 lrzsz before 0.13.0 Path Traversal via lrz Restricted Mode checkpath()
Attackers can overwrite arbitrary files via absolute paths in lrzsz restricted mode unless the pubdir feature is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-105840?
CVE-2026-105840 is a high-severity path traversal vulnerability in Uwe Ohse lrzsz, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
lrzsz before 0.13.0 contains a path traversal vulnerability in the lrz receive utility's restricted mode that allows malicious ZMODEM senders to write files outside the current directory using absolute pathnames. Because checkpath() in src/lrz.c only rejects '../' sequences unless built with --enable-pubdir, attackers can send files named with absolute paths to overwrite any file writable by the receiving user.
Weakness: CWE-22
Which versions are affected by CVE-2026-105840?
How do I fix CVE-2026-105840?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-105840 being exploited?
There is no known exploitation of CVE-2026-105840 in the wild and no public exploit code.
Sources
Also known as AZL-106667, DEBIAN-CVE-2026-105840, GHSA-3hwf-cvfh-5874, UBUNTU-CVE-2026-105840.