CVE-2026-92914 Overview
AVideo LoginControl contains an authentication bypass vulnerability in the PGP second factor verification flow. The verifyChallenge.json.php endpoint compares challenge responses using PHP loose equality (==) against an uninitialized session variable. Attackers who already possess a victim's password can bypass the second authentication factor by sending a parameter-less GET request. The comparison evaluates null == null as true and marks authentication as complete. The flaw is categorized under [CWE-287] Improper Authentication.
Critical Impact
An attacker with valid credentials for a target account can defeat the PGP-based second factor and complete authentication without possessing the PGP key, gaining full access to the victim's account.
Affected Products
- AVideo (WWBN/AVideo) platform
- AVideo LoginControl plugin
- AVideo deployments with PGP second factor authentication enabled
Discovery Timeline
- 2026-09-17 - CVE-2026-92914 published to NVD
- 2026-09-17 - Last updated in NVD database
Technical Details for CVE-2026-92914
Vulnerability Analysis
The vulnerability resides in the PGP second factor verification logic of the AVideo LoginControl component. The verification endpoint at verifyChallenge.json.php reads a user-supplied challenge response and compares it to a value stored in the PHP session. That session value is not initialized before comparison in all execution paths.
PHP's loose equality operator (==) treats two null values as equal. When both the submitted parameter and the session-stored expected challenge are absent, the comparison returns true. The endpoint then marks the second factor as satisfied and finalizes authentication. This transforms a two-factor login into a single-factor login for any account with a compromised password.
Root Cause
The root cause combines two defects. First, the challenge verification uses loose equality instead of a constant-time strict comparison. Second, the expected challenge value is not guaranteed to be initialized in the session before the comparison runs. The combination allows an uninitialized state to satisfy the check, violating the authentication invariant described in [CWE-287].
Attack Vector
An attacker who already knows a victim's primary credentials initiates a login. Instead of supplying a valid PGP-signed challenge response, the attacker issues a GET request to verifyChallenge.json.php with no parameters. The server evaluates null == null, returns success, and elevates the session to fully authenticated. No PGP key material, key access, or interaction with the legitimate user is required. Refer to the GitHub Security Advisory and the VulnCheck Security Advisory for the vendor and researcher description of the flaw.
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Stop Identity AttacksDetection Methods for CVE-2026-92914
Indicators of Compromise
- GET requests to verifyChallenge.json.php with no query parameters or an empty request body.
- Successful second factor completion events immediately following a login without a corresponding PGP challenge issuance in application logs.
- Session state transitions from partially authenticated to fully authenticated with no recorded challenge payload.
Detection Strategies
- Review web server access logs for requests to verifyChallenge.json.php that lack expected challenge parameters.
- Correlate authentication events to confirm that every second factor success is preceded by a matching challenge issuance for the same session.
- Alert on any authenticated session where the PGP second factor completed within milliseconds of the primary credential submission.
Monitoring Recommendations
- Ingest AVideo application and web server logs into a centralized log platform and retain full URL and parameter data.
- Track per-account frequency of second factor verifications and flag deviations from historical baselines.
- Monitor for successful logins originating from new IP addresses or user agents against accounts protected by PGP second factor.
How to Mitigate CVE-2026-92914
Immediate Actions Required
- Upgrade AVideo to the version identified as fixed in the GitHub Security Advisory GHSA-mvmf-jqg6-qhjf.
- Force password resets for any accounts that may already have compromised credentials, since possession of the password is the only precondition for exploitation.
- Invalidate active sessions after patching to ensure any pre-existing bypassed sessions are terminated.
Patch Information
Refer to the GitHub Security Advisory for the corrected version of AVideo and the fix commit that initializes the expected challenge and replaces loose equality with a strict, constant-time comparison. Additional guidance is available in the VulnCheck Security Advisory.
Workarounds
- Restrict network access to verifyChallenge.json.php at the reverse proxy or web application firewall until the platform is patched.
- Block requests to the verification endpoint that do not contain the expected challenge response parameter.
- Temporarily disable the PGP second factor feature and enforce an alternative multi-factor mechanism if one is available in the deployment.
# Example WAF rule concept: reject parameter-less requests to the challenge endpoint
# ModSecurity-style pseudo rule
SecRule REQUEST_URI "@endsWith /verifyChallenge.json.php" \
"id:1092914,phase:2,deny,status:400,\
chain,msg:'CVE-2026-92914 AVideo PGP 2FA bypass attempt'"
SecRule &ARGS "@eq 0"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
