CVE-2026-55578
Received Received - Intake

Terminal Command Injection in Pheditor

Publication date: 2026-07-27

Last updated on: 2026-07-27

Assigner: GitHub, Inc.

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.

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Meta Information

Published
2026-07-27
Last Modified
2026-07-27
Generated
2026-07-27
AI Q&A
2026-07-27
EPSS Evaluated
N/A
NVD
CVE-2026-55578
EUVD
EUVD-2026-49386

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
pheditor pheditor to 2.0.6 (exc)
pheditor pheditor 2.0.6

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-78 The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

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Executive Summary

CVE-2026-55578 is a vulnerability in Pheditor versions 2.0.1 to 2.0.5 where the terminal feature uses an incomplete blocklist to sanitize user commands before executing them. The blocklist fails to filter out pipe operators (|), backticks (`), and newline characters (0x0A), allowing authenticated users with terminal permissions to bypass the TERMINAL_COMMANDS allowlist and execute arbitrary OS commands as the web server user.

Detection Guidance

To detect this vulnerability, check if your Pheditor version is between 2.0.1 and 2.0.5. Inspect the terminal feature for unsanitized commands using pipe (|), backticks (`), or newline characters (0x0A). Test by attempting to execute commands with these characters through the terminal interface.

Impact Analysis

This vulnerability allows an authenticated attacker with terminal permissions to execute arbitrary OS commands on the server running Pheditor. This could lead to full system compromise, including unauthorized data access, modification, or deletion, as well as potential disruption of services. The high CVSS score of 8.8 indicates significant risk due to the potential for high confidentiality, integrity, and availability impacts.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating compliance requirements under GDPR (data protection) and HIPAA (health information privacy). Unauthorized command execution may result in data breaches, loss of data integrity, or service disruptions, all of which are critical compliance violations requiring breach notifications and potential penalties.

Mitigation Strategies

Immediately upgrade Pheditor to version 2.0.6 or later. Disable the terminal feature if not required. Review and restrict terminal permissions to only trusted users. Implement additional command validation by parsing commands into executable and arguments, validating against an allowlist, and escaping arguments.

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