CVE Intelligence
High Access control

CVE-2026-103659 — MISP: Object Distribution ACL Bypass via Event Flattening Exposes Organisation-Only Attributes

MISP contains an authorization bypass in the event flattening feature. When a user requests an event with the flatten option enabled, the application removes the Object containment from the query and returns object attributes as top-level event attributes. In doing so, the object-level distribution and sharing-group access control check was not re-applied to those attributes. As a result, a user who can view a community-distributed event could retrieve attributes belonging to organisation-only objects (distribution level 0) or objects restricted to a specific sharing group, even though the user's organisation does not have access to those objects. This constitutes an unauthorized disclosure of sensitive threat intelligence data. A secondary issue was introduced by the initial remediation: the fix reused the full Object contain conditions (including soft-delete state) as the gate for flattened attributes, causing an event owner requesting deleted attributes to lose all attributes whose parent object was still live. The final fix isolates the distribution ACL condition as the sole gate. Preconditions: - An authenticated user with access to a community-distributed event - The event contains at least one object with a distribution level or sharing group that restricts access beyond the event's own distribution Impact: - Unauthorized disclosure of attributes belonging to restricted objects - Potential exposure of organisation-specific threat intelligence to other organisations Affected versions: <2.5.48

Published Oct 1, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: CIRCL

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+2
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.23%
ahead of 13% of scored CVEs · Oct 15, 2026
Affects
MISP
MISP
CVSS base
7.1
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (MISP MISP).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
MISP MISP < 2.5.48 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
Low
User interaction
None
Scope
X
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
None
Availability (vulnerable system)
None
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.1 CVSS 4.0 High — — 5a6e4751-2f3f-4070-9419-94fb35b644e8 via NIST National Vulnerability Database
7.1 CVSS 4.0 High — — CIRCL via CVE Program (cve.org) e CISA ADP
CVSS: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 (score shown at the top: 5a6e4751-2f3f-4070-9419-94fb35b644e8)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-285 · Improper Authorization

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Audit administrative actions and access to resources outside each user’s normal pattern.
web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · misp/misp
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 7.1
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Oct 1, 2026 · CIRCL

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

Elsewhere on this site

MISP
every CVE for this vendor
Access control
same class
CWE-285
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-107276 MISP Email OTP Race Condition Allows One-Time Password to Be Consumed by Multiple Concurrent Requests 8d
  • CVE-2026-107278 MISP Object Sync Drops Objects and Attributes When Description Is Empty 8d
  • CVE-2026-107180 MISP: Forced TOTP Enrolment Bypassed via Non-Browser Request Types on otp_required Instances 9d
  • CVE-2026-107175 MISP Correlation Engine Fails to Refresh When Event Distribution or Sharing Group Changes 9d
  • CVE-2026-106513 MISP: Site-Admin Can Repoint Redis Workers to Attacker-Controlled Server via UI/API Configuration Change 9d
  • CVE-2026-104914 MISP: Soft-Deleted Attributes from Other Organizations Exposed via Attribute Search and Paginated View 13d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-103659 is "MISP: Object Distribution ACL Bypass via Event Flattening Exposes Organisation-Only Attributes", rated High. It affects MISP (MISP); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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