{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/azure-active-directory-b2c/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.1,"id":"CVE-2026-33843"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Azure Active Directory B2C"],"_cs_severities":["critical"],"_cs_tags":["authentication-bypass","privilege-escalation","azure-ad","cloud"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eCVE-2026-33843 is a critical vulnerability affecting Microsoft Azure Active Directory B2C. This authentication bypass vulnerability allows an attacker to elevate privileges over a network. The vulnerability stems from the use of an alternate path or channel during authentication, which can be exploited to gain unauthorized access. Microsoft has acknowledged this vulnerability and assigned it a CVSS v3.1 score of 9.1, indicating its critical severity. This flaw allows attackers to potentially bypass standard authentication mechanisms, leading to unauthorized access and control within the Azure AD B2C environment. Exploitation of this vulnerability can have severe consequences, as it allows attackers to perform actions with elevated privileges, potentially compromising sensitive data and resources.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies an Azure Active Directory B2C instance as a target.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious request to the authentication endpoint, exploiting an alternate path or channel.\u003c/li\u003e\n\u003cli\u003eThe crafted request bypasses the intended authentication checks.\u003c/li\u003e\n\u003cli\u003eThe system incorrectly validates the attacker\u0026rsquo;s request, granting unauthorized access.\u003c/li\u003e\n\u003cli\u003eThe attacker gains elevated privileges within the Azure AD B2C environment.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the elevated privileges to access sensitive data and resources.\u003c/li\u003e\n\u003cli\u003eThe attacker can modify user accounts, policies, or configurations.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-33843 allows an attacker to gain unauthorized access and elevate privileges within Microsoft Azure Active Directory B2C. This can lead to the compromise of sensitive data, modification of user accounts and policies, and disruption of services. The vulnerability\u0026rsquo;s critical severity, with a CVSS v3.1 score of 9.1, underscores the potential for significant damage, as it allows attackers to perform actions with elevated privileges.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the security update released by Microsoft to patch CVE-2026-33843 as soon as possible, as referenced in the advisory URL in the References section.\u003c/li\u003e\n\u003cli\u003eMonitor Azure Active Directory B2C logs for suspicious authentication attempts that may indicate exploitation of this vulnerability; deploy the Sigma rules provided to your SIEM and tune for your environment.\u003c/li\u003e\n\u003cli\u003eReview and enforce strong authentication policies for Azure Active Directory B2C to mitigate the risk of unauthorized access, complementing the patch for CVE-2026-33843.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-26T13:53:08Z","date_published":"2026-05-26T13:53:08Z","id":"https://feed.craftedsignal.io/briefs/2026-05-azuread-auth-bypass/","summary":"CVE-2026-33843 allows an unauthorized attacker to elevate privileges over a network in Microsoft Azure Active Directory B2C due to an authentication bypass using an alternate path or channel.","title":"CVE-2026-33843 Authentication Bypass in Microsoft Azure Active Directory B2C","url":"https://feed.craftedsignal.io/briefs/2026-05-azuread-auth-bypass/"}],"language":"en","title":"CraftedSignal Threat Feed — Azure Active Directory B2C","version":"https://jsonfeed.org/version/1.1"}