CVE-2026-17431 Command injection in PDF::WebKit
Attackers can execute arbitrary OS commands or modify files by supplying malicious paths to PDF::WebKit functions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-17431?
CVE-2026-17431 is a medium-severity command injection vulnerability in MITHALDU PDF::WebKit, published on 12 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
PDF::WebKit versions through 1.2 for Perl allow OS command injection via a 2-arg open() of the output path in to_pdf and of stylesheet paths in _style_tag_for.
to_pdf reads the generated PDF back from its path argument, and _style_tag_for reads each entry of the stylesheets list, by assigning the path to a local @ARGV and reading it with the diamond operator, which opens each @ARGV element with Perl's 2-arg open(). A value that begins or ends with a pipe ("| cmd", "cmd |") is run as a command rather than opened as a file, and one that begins with a redirect ("> path", ">> path") opens that path for write or append. to_file forwards its path argument to to_pdf and reaches the same read.
Any caller that forwards untrusted input as the output path or as a stylesheets entry can run a command under the process UID; with the "cmd |" form the command's output is returned in place of the PDF, and with the "> path" form the named file is truncated. Stylesheets may only be added to an HTML source, so a URL or file source exposes the output path alone.
Which versions are affected by CVE-2026-17431?
How do I fix CVE-2026-17431?
No fix has been published for CVE-2026-17431 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-2026-17431 being exploited?
There is no known exploitation of CVE-2026-17431 in the wild and no public exploit code.
Sources
Also known as GHSA-56v3-4wcg-g28h.