{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/vendors/flaskbb/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.1,"id":"CVE-2026-22659"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["FlaskBB \u003c= 2.2.0"],"_cs_severities":["high"],"_cs_tags":["authorization-bypass","vulnerability","web-application"],"_cs_type":"advisory","_cs_vendors":["FlaskBB"],"content_html":"\u003cp\u003eFlaskBB through version 2.2.0 is affected by an authorization bypass vulnerability, identified as CVE-2026-22659, which enables authenticated moderators to execute unauthorized administrative actions. This flaw allows a moderator, who normally has permissions only within specific forums, to extend their control to topics in forums they do not oversee. The exploitation mechanism involves submitting specially crafted batch requests where a legitimate topic ID from a permitted forum is included as an \u0026quot;anchor.\u0026quot; This tricks the application into passing its permission check, which is only applied to the first item in the batch. Subsequently, the attacker can perform actions like locking, unlocking, deleting, or hiding topics in forums they are not authorized to moderate, effectively escalating their privileges within the application. This vulnerability impacts all installations of FlaskBB up to version 2.2.0 and was addressed in commit acc88cf.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker obtains valid moderator credentials for a FlaskBB forum instance.\u003c/li\u003e\n\u003cli\u003eThe attacker identifies forums within the FlaskBB instance where their moderator account lacks administrative privileges.\u003c/li\u003e\n\u003cli\u003eThe attacker then identifies specific topics within these unauthorized forums that they wish to manipulate (e.g., delete, lock).\u003c/li\u003e\n\u003cli\u003eConcurrently, the attacker identifies a low-ID topic in a forum where their moderator account \u003cem\u003edoes\u003c/em\u003e possess legitimate moderation privileges. This topic will serve as the bypass \u0026quot;anchor.\u0026quot;\u003c/li\u003e\n\u003cli\u003eThe attacker constructs a batch request for a moderation action (e.g., lock, delete, hide) that includes both the legitimate low-ID topic from a permitted forum and the target topics from the unauthorized forums.\u003c/li\u003e\n\u003cli\u003eThe crafted batch request is submitted to the FlaskBB application's moderation endpoint.\u003c/li\u003e\n\u003cli\u003eDue to the authorization bypass vulnerability (CVE-2026-22659), the FlaskBB application performs its permission check only on the first topic in the batch (the legitimate low-ID topic). Since the attacker has permissions for this topic, the check passes.\u003c/li\u003e\n\u003cli\u003eThe application proceeds to execute the requested moderation action across all topics in the batch, including those in forums where the attacker otherwise lacks permission, achieving unauthorized administrative control.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful exploitation of CVE-2026-22659 allows an authenticated attacker to perform unauthorized administrative actions such as locking, unlocking, deleting, or hiding topics across any forum within a FlaskBB instance. While it does not grant full system access, it can lead to significant content integrity issues, disruption of forum operations, and reputational damage for the affected organizations. Organizations relying on FlaskBB for community management may face challenges in maintaining trust and order if malicious actors gain the ability to arbitrarily manipulate content in forums they do not control. The CVSS v3.1 Base Score for this vulnerability is 8.1, indicating a high severity risk.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch FlaskBB installations immediately to a version beyond 2.2.0, ensuring the fix introduced in commit acc88cf for CVE-2026-22659 is applied.\u003c/li\u003e\n\u003cli\u003eMonitor web server access logs for FlaskBB for any suspicious batch moderation requests, especially those originating from known moderator accounts manipulating topics outside their assigned forums, which could indicate exploitation of CVE-2026-22659.\u003c/li\u003e\n\u003cli\u003eReview FlaskBB application logs for unusual administrative actions or error messages related to topic moderation, which might signal attempts to exploit this authorization bypass vulnerability.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-10T14:18:45Z","date_published":"2026-07-10T14:18:45Z","id":"https://feed.craftedsignal.io/briefs/2026-07-flaskbb-auth-bypass/","summary":"An authorization bypass vulnerability exists in FlaskBB through version 2.2.0, allowing authenticated moderators to perform unauthorized administrative actions such as locking, unlocking, deleting, or hiding topics in forums they do not control. This is achieved by crafting batch requests that include a low-ID topic from a permitted forum, which bypasses permission checks applied only to the first item, and then executing actions on topics from unmoderated forums.","title":"FlaskBB Authorization Bypass Vulnerability (CVE-2026-22659)","url":"https://feed.craftedsignal.io/briefs/2026-07-flaskbb-auth-bypass/"}],"language":"en","title":"CraftedSignal Threat Feed - FlaskBB","version":"https://jsonfeed.org/version/1.1"}