What is authentication bypass?
Authentication Bypass is a type of attack that allows attackers to gain unauthorized access to a system by exploiting vulnerabilities in the authentication process.
Azərbaycanca: Autentifikasiya Bypass hücumu, təhlükəsizlik sistemlərindəki zəifliklərdən istifadə edərək, hücumçuların qanuni istifadəçi kimi sistemə daxil olmasına imkan verən bir hücum növüdür.
How it works
Authentication Bypass attacks exploit weaknesses in the authentication process, such as improper input validation, lack of token verification, or misconfiguration. This enables attackers to access the system as a legitimate user.
Defense checklist6
- 01
Regularly update systems and software
- 02
Implement strong authentication mechanisms (MFA)
- 03
Ensure proper input validation and token verification
- 04
Regularly review and update security policies and configurations
- 05
Conduct security testing and penetration testing
- 06
Monitor CVE and other security advisories
Real-world evidence
Incidents like CVE-2026-0257 (Qilin Ransomware), CVE-2026-48558 (SimpleHelp), CVE-2026-4773 (Magarsus Consulting Ltd. IDM-MFA), CVE-2026-65600 (Traefik), CVE-2025-50325 (BandiZip), CVE-2026-15348 (Premium Packages – Sell Digital Products Securely plugin for WordPress), CVE-2026-15612 (Logto), CVE-2026-63765 (Chatwoot), CVE-2026-15981 (SAML Single Sign On – SSO Login plugin for WordPress), CVE-2026-66139 (OpenStack Zaqar), CVE-2026-66006 (lakeFS), CVE-2026-13597 (微信二维码登陆 WordPress plugin) are examples of authentication bypass attacks.
Sources
- Qilin Ransomware Attackers Exploit PAN-OS Authentication Bypass for Initial Accesshackernews
- [KEV] CVE-2026-48558: SimpleHelp Authentication Bypass Vulnerabilitycisa_kev
- CVE-2026-4773: Improper validation of specified type of input vulnerability in Magarsus Consulting Ltd. Cnvd
- CVE-2026-65600: Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an autnvd
- CVE-2025-50325: BandiZip v.7.37 is affected by a Authentication Bypass Vulnerability. This vulnerability anvd
- CVE-2026-15348: The Premium Packages – Sell Digital Products Securely plugin for WordPress is vulnerable tnvd
- CVE-2026-15612: Logto bypasses OIDC nonce validation when the nonce claim is absent from the id_token, enanvd
- CVE-2026-63765: Chatwoot before 4.16.0 contains an authentication bypass vulnerability in the direct uploanvd
- CVE-2026-15981: The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bnvd
- CVE-2026-66139: OpenStack Zaqar through 22.0.0 allows authentication bypass via an EXTRA-SPEC header whennvd
- CVE-2026-66006: lakeFS through 1.83.0, fixed in commit 71a45ee, contains an authentication bypass vulnerabnvd
- CVE-2026-13597: The 微信二维码登陆 WordPress plugin through 1.3 does not properly validate WeChat webhook requestnvd
Other attack types
See also6
This guide is AI-written from the real incident sources skopnix collected — the examples above are drawn from those cited items, nothing is invented.