{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-56423: MISP Core: Broken access control allows instance-wide unauthorized deletion of event reports and sharing groups via bulk deletion endpoints","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-56423","status":"final","version":"1","initial_release_date":"2026-06-22T11:56:26.235Z","current_release_date":"2026-06-22T11:56:26.235Z","revision_history":[{"date":"2026-06-22T11:56:26.235Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.\n\nFor 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, $itemId, 'delete') for each selected report before deletion.\n\n\n\n\nFor Sharing Groups, SharingGroupsController::deleteSelection relied on the global perm_sharing_group capability rather than verifying ownership of each selected sharing group. This allowed a sharing-group-capable user to hard-delete sharing groups owned by other organisations, bypassing the per-object ownership gate used by the single-object delete action. The fix changed the callback to call SharingGroup::checkIfOwner($user, $itemId) for each selected sharing group.\n\n\n\n\nAn 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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-56423 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-56423"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-56423"},{"category":"external","summary":"github.com","url":"https://github.com/MISP/MISP/commit/ada02fa6d7558732aa4712fd5e9451cd8c5b7a64"},{"category":"external","summary":"github.com","url":"https://github.com/MISP/MISP/commit/f99b3f16ef22c7acf10e17036c777759cf031c15"}]},"product_tree":{"branches":[{"category":"vendor","name":"misp","branches":[{"category":"product_name","name":"misp","branches":[{"category":"product_version_range","name":"<=2.5.41","product":{"name":"misp misp <=2.5.41","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-56423","title":"MISP Core: Broken access control allows instance-wide unauthorized deletion of event reports and sharing groups via bulk deletion endpoints","notes":[{"category":"description","text":"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.\n\nFor 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, $itemId, 'delete') for each selected report before deletion.\n\n\n\n\nFor Sharing Groups, SharingGroupsController::deleteSelection relied on the global perm_sharing_group capability rather than verifying ownership of each selected sharing group. This allowed a sharing-group-capable user to hard-delete sharing groups owned by other organisations, bypassing the per-object ownership gate used by the single-object delete action. The fix changed the callback to call SharingGroup::checkIfOwner($user, $itemId) for each selected sharing group.\n\n\n\n\nAn 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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","baseScore":9.4,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}