Affected versions of MISP do not enforce parent-event visibility when serving cryptographic keys through CryptographicKeysController::view(). The vulnerable handler queried CryptographicKey directly using the supplied key ID and selected sensitive fields such as: * type * key_data * fingerprint but did not fetch or authorize the associated parent event first. The upstream commit explicitly states that cryptographicKeys/view could return a protected event’s signing key to any authenticated user. The fix adds parent_id and parent_type to the lookup and then enforces authorization through the associated event using fetchSimpleEvent($user, parent_id). If the parent is not an Event, access is limited to site administrators. Version affected: ≤2.5.45

Affected versions of MISP allow authenticated users to retrieve object-reference records by UUID through EventGraphTool::get_reference_data() without first checking whether the requester is authorized to view the object the reference belongs to. The vulnerable code queried ObjectReference.uuid directly and returned the matching row whenever it existed. Because no parent-object ACL was applied, a user who knew or obtained a reference UUID could retrieve information associated with an object outside their normal access scope. The commit explicitly states that any object reference could be returned by UUID without authorizing its parent object. The fix retrieves the referenced object's object_id and calls fetchObjectSimple() with the current user. If the user cannot access that parent object, MISP now returns NotFoundException instead of exposing the reference. Version affected: ≤2.5.45

Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile used the wildcard *. This bypasses the intended role restrictions applied to neighboring template-management operations. The upload handler accepts arbitrary content with only minimal checks and writes it into app/tmp/files/. A low-privileged or read-only user can therefore repeatedly upload files and consume server disk space without requiring perm_add or perm_template. The fix changes the ACL requirement from * to perm_add. The commit also rules out stronger impacts: uploaded files receive random names, path traversal/predictable overwrite is not available, the temporary directory is outside the web root, and the files are not directly served over HTTP. Therefore, the issue should not be described as arbitrary file overwrite, stored XSS, or RCE. Version affected: ≤2.5.45

Affected versions of MISP contain improper authorization checks in the freetext feed preview functionality. The preview performed correlation lookups against attributes from events without applying the requesting user's ACL, allowing restricted event correlations and associated event information to be exposed to users who could not otherwise access those events. The vulnerable queries were scoped only by attribute values and deletion status rather than MISP's event, organization, sharing-group, attribute, and object-level access controls. The same preview functionality also returned cross-feed correlation information without properly restricting the feed list to feeds visible to the caller. This exposed metadata for feeds that were not marked lookup_visible; one affected response additionally included the configured feed URL even though that value was not required by the feature. The fixes apply the caller's ACL to attribute correlation searches, remove feed URLs from correlation results, restrict cross-feed results according to feed visibility, and correct host-organization ID comparison so the authorization rules are applied consistently. Version affected: ≤2.5.45

Affected versions of MISP inconsistently enforced email-address visibility in DashboardsController::listTemplates(). The query always fetched User.email, while redaction happened only inside the non-REST rendering branch. As a result, the same authenticated user who saw redacted data in the normal HTML interface could request the REST/JSON representation and receive template owners’ email addresses without the intended privilege check. The fix moves the decision to a centralized User::canSeeEmails() authorization helper. Email addresses are now fetched only when the requester is a site administrator or the instance explicitly enables Security.disclose_user_emails. The same helper is also reused by other dashboard widgets to keep email-disclosure policy consistent. Version affected: ≤2.5.45

Affected versions of MISP contain insufficient validation of server-side outbound HTTP destinations in feed retrieval and TAXII discovery functionality. In feed processing, redirects were followed without validating the redirect scheme or destination. The original request headers were reused across redirect hops, meaning authentication headers or API credentials configured for a feed could be forwarded to a different host. Redirects could also target internal network resources, resulting in SSRF. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results to prevent re-resolution after validation. The TAXII discovery endpoint had a related incomplete SSRF defense. It used gethostbyname() and compared the result against only a few literal addresses. This missed cases including IPv6 loopback (::1), numeric host encodings such as 0x7f000001, and potentially multiple DNS records. The fix moves TAXII discovery to the shared URL egress validator. Together, these commits harden MISP's outbound URL handling against alternate-address representations, DNS-related bypasses, unsafe redirects, internal-host access, and cross-host credential forwarding. Version affected: ≤2.5.45

Affected versions of MISP validate the user-configurable homepage by checking only whether the supplied path begins with /. That check is insufficient because protocol-relative URLs such as //attacker.example also begin with / but resolve to an external origin in browsers. The vulnerable homepage value can be stored as a user setting and later used by the post-login routing logic. The commit explicitly identifies //attacker.example as a payload that passed validation and was emitted to the Location header after login. The fix introduces a shared InternalRedirectValidator that rejects URLs containing a host, scheme, userinfo, unsafe leading // or /\, malformed URLs, and control characters. It also revalidates homepage settings on read so legacy or internally written unsafe values cannot bypass the new storage-time validation. Version affected: ≤2.5.45

Affected versions of MISP contain inconsistent authorization checks across dashboard widgets that display organisation information. Several organisation-related widgets did not honor Security.hide_organisation_index_from_users. As a result, authenticated users without the perm_sharing_group permission could enumerate organisations even though the normal organisation index was intentionally hidden from them. The affected widgets included paths that: * returned organisation names and identifiers; * could expose additional organisation database fields through JSON export because unrestricted find('all') queries fetched full rows; * accepted limit=0 or negative values in a way that could effectively remove the result limit and return the entire organisation table. A related organisation-contributor leaderboard also ignored the same visibility setting. Its handler counted Event.orgc_id across the entire event table and mapped those IDs to organisation names, revealing every organisation with events regardless of whether the caller could see any of those events. The fix withdraws this widget entirely for users who lack organisation-index visibility. Version affected: ≤2.5.45

Affected versions of MISP expose organisation metadata through the dashboard organisation picker without applying the same visibility restrictions enforced by the normal organisation index and per-organisation view. The affected endpoint returned fields including: * organisation ID; * UUID; * name. When Security.hide_organisation_index_from_users was enabled, normal organisation enumeration was restricted, but the dashboard picker still queried all organisations. This allowed authenticated users to discover organisations that should have remained hidden from them. The fix calls Organisation::createConditions($this->Auth->user()) and appends the resulting ACL conditions to the picker query. Ordinary users are thereby limited to organisations associated with events or proposals they can already see, plus their own organisation, while users with the appropriate sharing-group privilege retain broader visibility. Version affected: ≤2.5.45

MISP's UiBeta theme collection view (app/View/Themed/UiBeta/Collections/view.ctp) performed a secondary query of member events by UUID without applying the caller's access control list (ACL). The CollectionsController::view() action correctly resolved collection element UUIDs through Event::fetchSimpleEvents($user, ...), which enforces per-user event ACL. However, the view template independently re-queried the same UUIDs using only an Event.uuid IN (...) condition, omitting the createEventConditions() authorization filter. Because collection element UUIDs are stored without server-side authorization against the referenced event (CollectionElementsController::add() accepts whatever UUID the collection owner posts), an authenticated user with view access to a collection could retrieve full details of events they are not permitted to read. The exposed data included event identifiers, info, dates, timestamps, creator organization, all event tags, and galaxy clusters (the latter attached via a cluster-scoped rather than event-scoped ACL check). This constitutes an authorization bypass at the presentation layer, allowing horizontal privilege escalation across event boundaries within the MISP instance.