CVE-2026-85538
Fix: MISP/MISP@d0a6f96CVE-2026-85538 is a CWE-863 vulnerability. O3 Security confirms whether CVE-2026-85538 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
An incorrect authorization vulnerability in MISP allowed authenticated users to delete attributes from events despite lacking the required perm_modify or perm_modify_org permissions. The…
Description
An incorrect authorization vulnerability in MISP allowed authenticated users to delete attributes from events despite lacking the required perm_modify or perm_modify_org permissions.
The affected attribute deletion paths relied on organization membership checks performed by MispAttribute::deleteAttribute() but did not consistently enforce MISP's event modification authorization rules. Consequently, a user belonging to the organization associated with an event could potentially delete individual attributes or perform bulk attribute deletion even when their assigned role was not authorized to modify the event.
This created an inconsistency between attribute editing and deletion: editing an attribute correctly used MISP's ACL::canModifyEvent() authorization logic, whereas the affected deletion operations could bypass these permission checks.
An authenticated attacker with access to an affected MISP instance and membership in the organization owning an event could exploit this flaw to remove attributes from that event, potentially causing unauthorized modification or loss of threat intelligence data.
The patch introduces a common authorization check for all affected deletion paths. Before deletion, MISP now resolves the associated events and verifies that the current user is authorized to modify each event using the same authorization mechanism used by normal event and attribute modification operations.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-85538 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-85538 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-85538. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-85538 in your dependencies?
O3 detects CVE-2026-85538 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.