CVE-2026-80427 bestzip before 2.2.6 and 3.0.x before 3.0.2 Argument Injection via Missing Option Delimiter
Attackers can execute arbitrary commands by passing malicious filenames starting with hyphens to the bestzip library, which fails to separate options from file paths.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-80427?
CVE-2026-80427 is a high-severity command injection vulnerability in nfriedly bestzip, published on 26 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
bestzip builds the argument list for the system zip utility without separating options from operands. The destination archive path and the caller-supplied source paths are passed to the child process with no -- delimiter between them, so any source entry beginning with a hyphen is interpreted by zip as an option rather than a file name. zip accepts -T to test the finished archive and -TT to name the command used to perform that test, so a source list containing those two entries and a command string causes zip to run that command through a shell once the archive has been written. An application that passes a file name or path it received from an untrusted source into the bestzip API therefore executes a command of the supplier's choosing. Versions 2.2.6 and 3.0.2 add the delimiter.
Weakness: CWE-88
Which versions are affected by CVE-2026-80427?
How do I fix CVE-2026-80427?
No fix has been published for CVE-2026-80427 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-80427 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-80427 exists.
Sources
Also known as GHSA-p87m-9567-rgcc.