Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret and disrupt the Jira integration via POST to /ac/installed during the pending-install window.. Mattermost Advisory ID: MMSA-2026-00654
MISP core contained multiple broken access-control flaws where authorization checks were performed against the wrong entity, or where ownership/editability checks were missing on write paths. In affected subsystems, a lower-privileged authenticated user with the relevant feature permission could cause the application to authorize one object but mutate another, or could modify objects that were merely visible rather than editable by the user’s organization.
The affected paths included:
* Event Reports tag removal: the route-authorized report could differ from the report ID used for tag detachment, enabling cross-organization tag removal from another event report
* Collection Elements bulk deletion: bulk deletion authorized against a collection whose ID matched the collection-element row ID, rather than the element’s actual parent collection, enabling deletion of elements from collections the user did not own.
* Analyst Data capture/update: nested analyst data updates could overwrite an existing record without applying the normal canEditAnalystData ownership check, enabling cross-organization overwrite of analyst data records.
* Template Elements editing: editing authorized against a template whose ID matched the template-element ID, rather than the element’s actual parent template, enabling unauthorized edits to another organization’s template elements.
* Decaying Model editing and mappings: write paths loaded models using view-scope access but did not verify edit ownership, enabling users to edit or remap visible models owned by another organization.
Successful exploitation could allow an authenticated user with subsystem-specific permissions to perform unauthorized cross-organization modifications or deletions of MISP data, resulting in integrity loss, unauthorized tampering with shared intelligence, and disruption of analyst workflows.
The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol.
The application used the PHP session identifier (session_id()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking.
Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that identifier after authentication.
The OAuth state value was also not implemented as a dedicated, single-use nonce. This weakened CSRF protections and increased the risk of replay attacks against the OAuth callback process.
The authentication flow further failed to enforce HTTPS for the configured OAuth redirect URI. If a non-HTTPS redirect URI was used, OAuth authorization codes and access tokens could traverse the network in plaintext, exposing sensitive credentials to network attackers.
Finally, OAuth error responses containing attacker-controlled GET parameters were logged verbatim. An attacker could inject control characters or crafted log content, leading to log forging, log injection, or corruption of audit records.
The fix introduces:
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A dedicated cryptographically random OAuth state value.
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Single-use state validation and invalidation.
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Constant-time state comparison using hash_equals().
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Session identifier rotation after successful authentication.
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Enforcement of HTTPS-only redirect URIs.
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Sanitized and length-limited logging of OAuth error parameters.
AAD Authentication Plugin (OAuth 2.0 / Azure Active Directory integration)
MISP allowed a site administrator to configure an arbitrary filesystem path for the NDJSON error log used by JsonLogTool. Because log entries can include attacker-controlled content, an authenticated attacker with site administrator privileges could direct log output to a PHP file in a web-accessible directory and inject PHP code through logged data. Accessing the resulting file could lead to remote code execution with the privileges of the web server process.
The fix restricts log destinations to existing directories beneath APP/tmp/logs or /var/log, requires absolute paths, rejects stream wrappers and traversal-related input, and limits filenames to .log or .ndjson extensions while disallowing executable extension segments.
MISP allowed an authenticated site administrator to set the Kafka_rdkafka_config setting to an arbitrary filesystem path. MISP subsequently parsed the referenced INI file and passed its options to rdkafka. A crafted attacker-controlled configuration file could use rdkafka options such as plugin.library.paths to load an external library, resulting in arbitrary code execution with the privileges of the MISP process. An attacker could leverage a MISP-writable location, such as an uploaded file or administrative image, to host the malicious configuration file.
The issue is fixed by restricting the setting to absolute .ini files located only in approved configuration directories outside the webroot and MISP upload targets.
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to enforce administrator authorization on the {{setDefaultInstance}} call within the {{/gitlab connect}} command handler, which allows any authenticated user to overwrite the global default GitLab instance configuration via the {{/gitlab connect <instance-name>}} slash command.. Mattermost Advisory ID: MMSA-2026-00644
MISP Core contained broken access-control checks in the bulk deletion flows for Event Reports and Sharing Groups. The affected deleteSelection handlers authorized deletion using broad role-level permissions instead of validating authorization for each selected object.
For Event Reports, EventReportsController::deleteSelection relied on the global perm_add capability rather than a per-report ownership/authorization check. As a result, a contributor-level user could submit report IDs or UUIDs for reports belonging to other organisations and hard-delete them instance-wide. The fix changed the callback to call EventReport::fetchIfAuthorized($user, $itemId, 'delete') for each selected report before deletion.
For Sharing Groups, SharingGroupsController::deleteSelection relied on the global perm_sharing_group capability rather than verifying ownership of each selected sharing group. This allowed a sharing-group-capable user to hard-delete sharing groups owned by other organisations, bypassing the per-object ownership gate used by the single-object delete action. The fix changed the callback to call SharingGroup::checkIfOwner($user, $itemId) for each selected sharing group.
An authenticated attacker with the relevant broad role permission could abuse the affected bulk deletion endpoints to delete objects outside their organisation’s authorization scope, causing loss of event-report content or sharing-group configuration across the instance.
IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution combined with an authentication bypass that allows an unauthenticated attacker to execute arbitrary code on the host system, resulting in complete compromise
IBM Engineering Workflow Management 7.0.3 through 7.0.3 Interim Fix 020, and 7.1 through 7.1 Interim Fix 007 is vulnerable to cross-site scripting. This vulnerability allows an authenticated user to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.