MISP Event Graph Object Reference Lookup Exposes References from Unauthorized Objects

published 2026-09-07 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-72396

cvss: 4.3; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits: 0; none known

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

Patch / fix

links 1

github.com/MISP/MISP@c0cb5c9 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-09-08)

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/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
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

MISP MISP

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

References

github.com /MISP/MISP/commit/c0cb5c9f8
patch

Sources

CVE List CVE-2026-86451
NVD CVE-2026-86451

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary