CVE-2026-76207

Executive Summary

CVE-2026-76207 is a two-factor authentication (2FA) bypass vulnerability affecting phpMyFAQ versions prior to 4.1.7. The flaw resides in the authentication flow where remember-me tokens are generated and issued before 2FA verification completes, allowing an attacker with valid credentials to obtain a persistent authentication cookie, skip the 2FA challenge entirely, and subsequently replay that cookie to achieve full authenticated access to the application. With a CVSS score of 8.1 (High), the vulnerability exposes the confidentiality and integrity of the phpMyFAQ installation to authenticated attackers, effectively neutralizing the security control that 2FA is intended to provide.

Technical Analysis

The vulnerability class is CWE-304 — Missing Steps in Authentication Mechanism. The underlying defect is a logic flaw in the authentication state machine of phpMyFAQ versions prior to 4.1.7. When a user initiates a login session, the application processes credential validation and session/token issuance as partially overlapping steps rather than strictly sequential phases.

Specifically, the NVD description indicates that "remember-me tokens are issued before 2FA verification completes." In a correct implementation, the authentication flow should be:

1. Credential verification (username/password)
2. 2FA challenge issuance
3. 2FA verification (TOTP, SMS, or other second factor)
4. Session establishment and persistent cookie (remember-me) issuance — only after ALL preceding steps pass

In the vulnerable flow, the application skips or permits a bypass of step 3 regarding the remember-me token lifecycle. The remember-me cookie is generated and stored client-side (and presumably server-side in a token store) before the 2FA step is enforced. This creates a race condition or out-of-order processing where the token exists and is considered valid by the server even though the user never completed step 3.

The attack surface is the web authentication interface — the login page and subsequent authenticated session endpoints. The vulnerability does not require network adjacency; it is remotely exploitable over HTTP(S). The prerequisite is valid credentials (username and password), meaning the attacker already possesses legitimate credentials via phishing, credential stuffing, database leakage, or brute force. The attacker leverages the remember-me token as a session persistence mechanism to bypass the 2FA gate that would normally stop them at the credential stage.

Insufficient technical detail is available regarding the exact code path, function names, or endpoint URLs involved. The NVD description does not disclose whether the flaw exists in a specific PHP function, controller, or middleware component. What is clear from the mechanism description is that the token issuance and 2FA enforcement are decoupled in a way that permits token validity independent of 2FA completion.

Exploitation Scenarios

The attack chain for CVE-2026-76207 proceeds as follows, with the caveat that no public PoC exists and the chain is inferred from the vulnerability class and NVD description:

Step 1 — Reconnaissance / Target Identification
The attacker identifies a phpMyFAQ instance running a version prior to 4.1.7. This can be achieved via Shodan (with fingerprints such as "generator:phpMyFAQ") or through banner/header inspection. The attacker confirms the target version via HTTP response headers, meta tags, or known static resource paths that encode the version number. Concurrently, the attacker obtains valid credentials for a user account on the target. This may be achieved through phishing targeting FAQ administrators, credential stuffing from prior breach data, or brute-forcing low-privilege accounts with weak passwords.

Step 2 — Triggering the Flaw
The attacker submits valid credentials through the standard login form. The application authenticates the credentials successfully, and — due to the flaw — issues a remember-me token/cookie at this point, before the 2FA challenge is presented or enforced. The attacker captures this token response (e.g., via the Set-Cookie header or the JSON/session response body). Critically, the attacker does NOT need to solve or complete the 2FA challenge.

Step 3 — Execution / Token Replay
The attacker stores the captured remember-me cookie. They then make authenticated requests to the application (e.g., accessing the admin dashboard, editing FAQ content, or invoking administrative API endpoints) while presenting the remember-me cookie. Because the server-side token store recognizes the remember-me token as valid, the application grants full authenticated access without requiring the 2FA step that the attacker never completed. The token can be replayed persistently across sessions, providing long-lived access.

Step 4 — Post-Exploitation Impact
Once authenticated, the attacker has the same privileges as the compromised account. For an administrator account, this includes full read/write access to the FAQ knowledge base: modifying, deleting, or injecting malicious content into FAQ articles; accessing the user management console; modifying application configuration; and potentially extracting database credentials or other sensitive data exposed through admin functions. The integrity impact is direct (content manipulation), and the confidentiality impact is realized through access to restricted FAQ content and underlying system data.

No public PoC is available; this attack chain is inferred from the vulnerability class and the NVD description.

Impact Assessment

CVSS Analysis: The CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N yields a score of 8.1 (High). Key observations:

• Attack Vector: Network — remotely exploitable over the internet.
• Attack Complexity: Low — no special conditions or timing windows required; the flaw triggers during normal login flow.
• Privileges Required: Low — the attacker only needs valid low-privilege credentials (not admin), though impact scales with the compromised account's privileges.
• User Interaction: None — no victim action required beyond the attacker's own login attempt.
• Confidentiality Impact: High — full access to FAQ content, user data, and potentially backend configuration.
• Integrity Impact: High — attacker can modify FAQ content and system settings.
• Availability Impact: None.

Business Impact: phpMyFAQ is a widely deployed open-source FAQ management system used by enterprises for customer support, internal knowledge bases, and compliance documentation. A 2FA bypass on this system undermines the account security posture of organizations that have mandated 2FA as a compensating control for credential compromise. Given that the attacker must already possess valid credentials, this vulnerability effectively removes the second layer of defense that many organizations rely on to protect against credential-theft-based intrusions.

Blast Radius: The vulnerability affects all phpMyFAQ installations running version < 4.1.7 that have 2FA enabled. The blast radius is proportional to the sensitivity of the FAQ content and any integration points (e.g., ticketing systems, CRM data, or internal processes that reference FAQ content). For organizations that use the FAQ as a canonical reference for operational procedures, the integrity impact equates to potential misinformation propagation.

Detection Guidance

Sigma Rule

title: phpMyFAQ Remember-Me Token Issued Without 2FA Completion
id: c1f3b4a2-7d9e-4a5b-8c3d-2f6e9a1b4c7d
status: experimental
description: Detects login sequences to phpMyFAQ where a remember-me token is set
             but no 2FA verification event precedes successful authenticated access.
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-76207
author: Valtersit Threat Intelligence
date: 2026/01/01
logsource:
    category: application
    product: phpmyfaq
detection:
    selection_token:
        cs4:message|contains: 'remember-me'
        cs4:status: 'success'
    selection_2fa_absent:
        cs4:event: '2FA_VERIFY'
        cs4:status: 'success'
    condition: selection_token and not selection_2fa_absent
level: high
falsepositives:
    - Legitimate users who complete 2FA via a method not logged by the
      application logger (unlikely but possible).

YARA Rule

rule phpMyFAQ_2FA_Bypass_Indicator
{
    meta:
        author = "Valtersit Threat Intelligence"
        description = "Detects patterns in phpMyFAQ source indicating remember-me token issuance before 2FA enforcement"
        cve = "CVE-2026-76207"
        date = "2026-01-01"
    strings:
        $s1 = "remember-me" ascii wide nocase
        $s2 = "setcookie" ascii wide nocase
        $s3 = "2fa" ascii wide nocase
        $s4 = "totp" ascii wide nocase
        $s5 = "session_regenerate_id" ascii wide nocase
    condition:
        all of ($s1, $s2, $s3) and 1 of ($s4, $s5)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-76207 - phpMyFAQ 2FA Bypass - Remember-Me Cookie Set Before 2FA Completed"; flow:established,to_server; http.response_body; content:"remember-me"; nocase; http.response_body; content:"set-cookie"; nocase; pcre:"/set-cookie:\s*[^;\r\n]*remember[^;\r\n]*/i"; sid:5076207; rev:1; metadata:cve CVE-2026-76207; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-76207;)

Elastic Detection

sequence by source.ip with maxspan=30s
  [network where destination.port == 443 and http.request.method == "POST"
   and url.path like "*login*" and http.request.body.text like "*password*"]
  [network where http.response.status_code == 200
   and http.response.headers["set-cookie"] like "*remember*"]
  [network where http.request.method != "POST" and http.request.method != "OPTIONS"
   and http.response.status_code == 200 and not http.request.headers.authorization like "*Basic*"]

Splunk SPL Query

index=web earliest=-15m
| search source="/var/log/phpmyfaq/access.log" OR sourcetype="apache:access"
| rex field=_raw "Set-Cookie:\s+(?<cookie>[^;\r\n]+)"
| search cookie="*remember*"
| rex field=_raw "POST\s+(?<uri_path>\S+)\s+HTTP"
| search uri_path="*login*"
| join type=inner source.ip [ search index=web earliest=-15m
    | rex field=_raw "GET\s+(?<uri_path2>\S+)\s+HTTP"
    | eval authenticated = mvappend(authenticated, "session")
    | table source.ip uri_path2 ]
| where isnull(authenticated)
| stats count by src_ip, dest_host, uri_path, cookie
| where count > 0

Wazuh OSSEC Rule

<group name="phpmyfaq,">
  <rule id="500207" level="12">
    <decoded_as>json</decoded_as>
    <field name="app">phpmyfaq</field>
    <field name="event">login_success</field>
    <field name="remember_me">true</field>
    <description>CVE-2026-76207: phpMyFAQ login success with remember-me token while no 2FA verification event observed</description>
    <group>authentication,bypass,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED. No patch evidence has been independently verified from any tracked source as of this writing. The CNA metadata indicates the fix version is 4.1.7 (phpMyFAQ before 4.1.7 is vulnerable), but the vendor advisory has not been located or verified. Treat the upgrade guidance below with appropriate caution until the advisory is confirmed.

Immediate Mitigations (to apply while awaiting patch verification):

1. Disable remember-me functionality: If the phpMyFAQ instance supports configuration to disable persistent login / remember-me tokens, disable this feature immediately. This removes the attack primitive entirely, as the flawed token cannot be issued.
2. Restrict authentication to trusted IP ranges: Implement network-level access control (e.g., firewall rules, reverse-proxy allowlists) so that the phpMyFAQ login interface is only reachable from approved networks or via VPN. This reduces the remote attack surface.
3. Enforce strong password policies and monitor for brute force: Since the attack requires valid credentials, enforce complex passwords and enable account lockout policies. Monitor authentication logs for repeated failed login attempts or unusual login patterns that indicate credential-stuffing campaigns.
4. Audit active sessions and tokens: Review server-side session/token stores for remembered sessions that do not have corresponding 2FA verification audit events. Purge all remembered sessions to force re-authentication.

Patch / Upgrade Steps:

1. Verify the fix: Monitor the phpMyFAQ GitHub repository (https://github.com/thorsten/phpMyFAQ) and the project's official communications for the 4.1.7 release announcement and advisory.
2. Upgrade phpMyFAQ to version 4.1.7 or later once verified. Follow the project's standard upgrade procedure: back up the database and configuration files, replace the application files, and run any required database migrations.
3. Test the upgrade in a staging environment first, with 2FA enabled, to confirm that remember-me tokens are no longer issued prior to 2FA completion.

Long-Term Hardening:

1. Enforce 2FA for all accounts with no exception paths. Review the 2FA enforcement policy to ensure it cannot be bypassed by alternate authentication mechanisms.
2. Implement session management best practices: ensure cookies are HttpOnly, Secure, SameSite=Strict, and that server-side session IDs are rotated after authentication.
3. Integrate security monitoring: forward phpMyFAQ authentication logs to a centralized SIEM and implement detection rules similar to those provided above.
4. Conduct periodic security reviews of authentication flows, particularly for open-source applications, and subscribe to project security advisories.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-76207
2. phpMyFAQ Project: https://github.com/thorsten/phpMyFAQ (for patch verification and release announcements)
3. CWE-304 Reference: https://cwe.mitre.org/data/definitions/304.html — Missing Steps in Authentication Mechanism
4. ATT&CK T1078 — Valid Accounts: https://attack.mitre.org/techniques/T1078/
5. Shodan search reference for phpMyFAQ fingerprinting: https://www.shodan.io/search?query=phpmyfaq

Known Exploit-in-the-Wild Evidence: None confirmed at this time. No public PoC, no Nuclei template, and no exploit code has been identified. No CISA KEV inclusion.

Threat Actor Campaigns: No specific campaigns attributed to this CVE have been identified. The vulnerability class (2FA bypass via token issuance order) is attractive to actors performing credential-stuffing and account-takeover operations, so monitoring for exploitation attempts is advised.