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Fencer Vulns
high 8.8

CVE-2026-54361 json

MISP mass assignment vulnerabilities allow unauthorized modification of ownership and delegation records

published 2026-06-12 4 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-36554

cvss
8.8
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

MISP contained multiple mass assignment vulnerabilities in the handling of collections, tag collections, event delegations, and shadow attributes. Several controller actions accepted user-supplied fields that should have remained server-controlled, including record identifiers and ownership-related fields such as id, org_id, orgc_id, and user_id.

An authenticated attacker with access to the affected endpoints could craft requests containing protected fields in order to alter object ownership, redirect an update to another record, overwrite existing event delegation requests, or modify shadow attribute proposals belonging to another organization. This could result in unauthorized modification of MISP objects and, depending on object visibility and sharing configuration, unauthorized access to or transfer of sensitive threat intelligence data.

The issue was fixed by explicitly pinning ownership and identity fields to their stored values during edit operations and by removing user-supplied primary keys from create-only save paths.

Affected components:

* CollectionsController::edit() * EventDelegationsController::delegateEvent() * ShadowAttributesController::edit() * TagCollectionsController::edit()915 * TagCollectionsController::editWithTags()

Attack requirements: The attacker must be authenticated and able to reach the affected MISP endpoints. No user interaction is required.

Patch / fix

  • misp misp 2.5.40

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/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

Affected products

  • misp misp

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

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.