CVE-2026-54398Network attack vector

Unauthorized sharing-group assignment via misvalidated object payload

Published Jun 12, 2026 · Updated Jun 12, 2026

Incorrect authorization in MISP before 2.5.40 allows remote authenticated users to assign objects to unauthorized sharing groups. ObjectsController merges Object fields into the top-level request, then validates the removed nested Object structure; embedded attributes also lack individual sharing-group checks. Object-edit permission and a crafted distribution value of 4 are required, enabling unauthorized distribution metadata changes and limited disclosure of hidden sharing-group names.

CVSS severity5.3
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in MISP before 2.5.40 allows remote authenticated users to assign objects to unauthorized sharing groups. ObjectsController merges Object fields into the top-level request, then validates the removed nested Object structure; embedded attributes also lack individual sharing-group checks. Object-edit permission and a crafted distribution value of 4 are required, enabling unauthorized distribution metadata changes and limited disclosure of hidden sharing-group names.

The record

CVE
CVE-2026-54398
Published
Jun 12, 2026
Updated
Jun 12, 2026
Vendor
MISP Project
Product
MISP
Classifications
CWE-863, CAPEC-1, CAPEC-180, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.5.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MISP Project · MISPversion=0 <2.5.40

Published CVSS scores

5.3CIRCLCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
CAPEC-180Exploiting Incorrectly Configured Access Control Security Levels
T1565.001Data Manipulation: Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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