Is CVE-2026-55578 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-55578?

CVE-2026-55578 has a CVSS v3 severity of HIGH (8.8).

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CVE-2026-55578

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.