CVE-2026-40487 | gitroomhq postiz-app up to 2.21.5 cross site scripting (GHSA-44wg-r34q-hvfx)

VDB-358188 · CVE-2026-40487 · GHSA-44WG-R34Q-HVFX GITROOMHQ POSTIZ-APP UP TO 2.21.5 CROSS SITE SCRIPTING HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.1 $0-$5k 0.76+ Summaryinfo A vulnerability described as problematic has been identified in gitroomhq postiz-app up to 2.21.5. The affected element is an unknown function. The manipulation results in cross site scripting. This vulnerability was named CVE-2026-40487. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended. Detailsinfo A vulnerability was found in gitroomhq postiz-app up to 2.21.5. It has been classified as problematic. Affected is an unknown code block. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes: Postiz is an AI social media scheduling tool. Prior to version 2.21.6, a file upload validation bypass allows any authenticated user to upload arbitrary HTML, SVG, or other executable file types to the server by spoofing the `Content-Type` header. The uploaded files are then served by nginx with a Content-Type derived from their original extension (`text/html`, `image/svg+xml`), enabling Stored Cross-Site Scripting (XSS) in the context of the application's origin. This can lead to session riding, account takeover, and full compromise of other users' accounts. Version 2.21.6 contains a fix. The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-40487 since 04/13/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007. Upgrading to version 2.21.6 eliminates this vulnerability. The upgrade is hosted for download at github.com. Productinfo Vendor gitroomhq Name postiz-app Version 2.21.0 2.21.1 2.21.2 2.21.3 2.21.4 2.21.5 Website Product: https://github.com/gitroomhq/postiz-app/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 6.2 VulDB Meta Temp Score: 6.1 VulDB Base Score: 3.5 VulDB Temp Score: 3.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 8.9 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Cross site scripting CWE: CWE-79 / CWE-94 / CWE-74 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: postiz-app 2.21.6 Timelineinfo 04/13/2026 CVE reserved 04/18/2026 +5 days Advisory disclosed 04/18/2026 +0 days VulDB entry created 04/18/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-44wg-r34q-hvfx Status: Confirmed CVE: CVE-2026-40487 (🔒) GCVE (CVE): GCVE-0-2026-40487 GCVE (VulDB): GCVE-100-358188 Entryinfo Created: 04/18/2026 09:26 Changes: 04/18/2026 09:26 (65) Complete: 🔍 Cache ID: 99:201:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸