7.1 High

MISP Guard, a proxy-based security filter for MISP feed distribution, contains a case-sensitivity flaw in multiple policy enforcement…

CVE-2026-116469

MISP Guard, a proxy-based security filter for MISP feed distribution, contains a case-sensitivity flaw in multiple policy enforcement checks. The functions checkrequiredtaxonomyexists, checkrequiredtaxonomytagsallowed, checkblockedattributecategories, and checkblockedanalystdatasharinggroupsuuids performed case-sensitive string comparisons when matching event tags, attribute categories, and sharing-group UUIDs against configured allow/block lists. An attacker with the ability to create or modify events in a MISP instance (or a connected instance that pushes events through the guard) could craft events using different letter case in taxonomy tag names, attribute categories, or sharing-group UUIDs to bypass the configured security policies. For example, if the policy requires the 'tlp' taxonomy with only 'tlp:clear' allowed, an event tagged 'TLP:AMBER' would not be recognized as belonging to the 'tlp' taxonomy and would therefore not be checked against the allowed-tags list, resulting in the event being forwarded to feed consumers. Similarly, a blocked attribute category such as 'Person' would not match a configured block entry of 'person', allowing the attribute to pass through the…

Assessment

CVSS: 7.1 (v4.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 26 October 2026
Last updated: 27 October 2026
Weakness: CWE-178, CWE-20
Assigner: 5a6e4751-2f3f-4070-9419-94fb35b644e8

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

At the source

References

https://github.com/MISP/misp-guard/commit/9868b1d93fc9cc40cc7c69ca11c86afd825bbc1c

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