CVE-2026-55578 Pheditor: Incomplete command sanitization in terminal feature allows RCE via pipe operator, backtick substitution, and newline injection
Authenticated users can execute arbitrary OS commands via the terminal feature due to incomplete input sanitization, allowing remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55578?
CVE-2026-55578 is a high-severity command injection vulnerability in pheditor, published on 27 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Pheditor is a single-file editor and file manager written in PHP. From version 2.0.1 to before version 2.0.6, the terminal feature in Pheditor uses an incomplete character blocklist to sanitize user-supplied commands before passing them to shell_exec(). After the fix for GHSA-9643-6xjp-vx57 (which added $ to the blocklist), the characters | (single pipe), ` (backtick), and the newline byte (0x0A) remain unblocked. An authenticated user with the terminal permission (enabled by default) can leverage any of these to bypass the TERMINAL_COMMANDS allowlist and execute arbitrary OS commands as the web server user. This issue has been patched in version 2.0.6.
Weakness: CWE-78
Which versions are affected by CVE-2026-55578?
2 open source packages ship an affected version, including pheditor/pheditor.
| Package | Affected | Fixed in |
|---|---|---|
pheditor/pheditor Packagist | From 2.0.1 | 2.0.6 |
pheditor/pheditor Packagist | From 2.0.1 | 2.0.6 |
How do I fix CVE-2026-55578?
Upgrade pheditor/pheditor to 2.0.6 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-55578 being exploited?
There is no known exploitation of CVE-2026-55578 in the wild and no public exploit code.
Sources
Also known as GHSA-wg4w-wr5q-6vjc.