CVE-2026-77751
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk40th percentile - higher than 40% of all known CVEs
Summary
A path traversal vulnerability in MISP during STIX 2 import and MISP-to-STIX 2 export. MISP object names were not sufficiently validated before being used in filesystem paths for template resolution, allowing escape from the template directory and loading a definition.json from another location. An attacker could supply a malicious object name (e.g., containing ../) via a custom STIX object or a persistent MISP event.
Risk Assessment
The risk includes unauthorized reading of local files (if a suitable definition.json exists outside the template directory) and modification of metadata or semantics of converted objects. The vulnerability can be exploited in different security contexts, especially when export is performed with higher privileges.
Recommendation
Apply patches provided by MISP that introduce strict validation of object template names (only letters, digits, hyphens, and underscores allowed). Update MISP to a version containing these patches and ensure that rejected names are replaced with the generic unknown-template name.
Other vulnerabilities in MISP
See all- CVE-2026-61474Medium
An improper authorization check in MISP's attribute creation endpoint allowed an authenticated user with permission to add attributes to submit a sharing_group_id without triggering the corresponding sharing group authorization check, as long as the attribute distribution value was not explicitly set to 4 — 'sharing group'.
- CVE-2017-14337High
In MISP versions before 2.4.80, when configured with X.509 certificate authentication alongside a non-MISP external user management API, an unauthenticated user can gain access as an arbitrary user if the API returns an empty value.
- CVE-2026-10868Critical
MISP has a mass assignment vulnerability in the user edit functionality (UsersController::edit()). An authenticated attacker can modify the user ID in the request, leading to updates on another user's account.
- CVE-2026-10611Critical
MISP contains an authentication bypass vulnerability when LDAP mixed authentication is enabled with OTP enforcement. An authenticated user can bypass the OTP step and access the application without providing a TOTP, HOTP, or email OTP code.
- CVE-2024-29859Critical
In MISP before version 2.4.187, the add_misp_export function in app/Controller/EventsController.php does not properly check for a valid file upload.
- CVE-2024-25674Critical
An issue was discovered in MISP before version 2.4.184 related to insecure organization logo uploads due to a lack of checks for file extension and MIME type.
- CVE-2023-50918Critical
In app/Controller/AuditLogsController.php in MISP before version 2.4.182, ACLs for audit logs are mishandled.
- CVE-2023-48659Critical
An issue was discovered in MISP before version 2.4.176 related to mishandling parameter parsing in app/Controller/AppController.php.
- CVE-2022-29528Critical
An issue was discovered in MISP before version 2.4.158 related to PHAR deserialization.
- CVE-2021-39302Critical
MISP version 2.4.148, in certain configurations, allows SQL injection via the $conditions['org'] value in the app/Model/Log.php file.
Original NVD description (English source)
A path traversal vulnerability existed in the handling of MISP object template names during STIX 2 import and MISP-to-STIX 2 export. MISP object names are passed to PyMISP's object-template resolution mechanism, which constructs a filesystem path by joining the configured MISP object-template directory, the object name, and definition.json. An object name originating from untrusted STIX or MISP content was not sufficiently restricted before being used in this filesystem path. An attacker able to supply a crafted object name containing path separators or traversal sequences such as ../ could therefore cause template resolution to escape the expected template directory and attempt to load a definition.json file from another location accessible to the process. During STIX 2 import, an attacker-controlled x_misp_name from a custom STIX object could directly reach this template-resolution mechanism. The issue could also become persistent. A malicious object name stored in a MISP event could later be processed again during STIX 2 export. Consequently, content originally introduced in one security context could trigger filesystem access later when the event is exported by a process operating with different or greater privileges. If a suitable definition.json file exists outside the intended template directory, its contents may be interpreted as a MISP object template and fields from that file copied into the converted object. This can result in unintended disclosure of locally accessible data represented by the template file and modification of the resulting object's metadata or semantics. The patches introduce strict validation of object-template names. Valid names are restricted to a single path component containing letters, digits, hyphens, or underscores. Names that do not meet these requirements are replaced with the generic unknown-template name before reaching PyMISP template resolution. The original rejected name is preserved in the object's comment and a warning is generated, preventing traversal while retaining the source information.