CVE-2026-104908: MISP Decaying Model Import Mass Assignment Allows Cross-Organization Model Overwrite and Default Flagging

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.3%

EPSS score, percentile 21.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

7.1 High

CVSS v4.0 base score, given by the CNA

What should I do?

The import handler now builds the model record from an explicit allow-list of permitted fields (name, parameters, description, ref, formula, version, enabled … Full textSolution from the CVE record.

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• before 2.5.48

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Solution (from the CVE record)

The import handler now builds the model record from an explicit allow-list of permitted fields (name, parameters, description, ref, formula, version, enabled, all_orgs) using array_intersect_key, discarding any unlisted keys including nested model objects. The organisation identifier and default flag are set unconditionally after filtering. The save operation is preceded by an explicit create() call and the data is wrapped in the proper model key, preventing the ORM from interpreting attacker-supplied nested keys as separate model attributes.

Advisories and patches

• Security patch (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

MISP contains an improper input validation vulnerability in the decaying model import functionality. The import endpoint was intended to create a new decaying model belonging exclusively to the importing user's organisation, with the default flag forced to off. However, the application stripped only the top-level id and uuid fields and pinned org_id and default on the outer array before saving t…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-104908 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 2 Oct 2026.
• The CVE record carries a CVSS v4.0 base score of 7.1 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 21.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

MISP Decaying Model Import Mass Assignment Allows Cross-Organization Model Overwrite and Default Flagging

MISP contains an improper input validation vulnerability in the decaying model import functionality. The import endpoint was intended to create a new decaying model belonging exclusively to the importing user's organisation, with the default flag forced to off. However, the application stripped only the top-level id and uuid fields and pinned org_id and default on the outer array before saving the data flat. A user with decaying-model permissions could supply a nested model key carrying its own primary key, organisation identifier, and default flag, which bypassed those guards during the save operation. Impact: - A user with perm_decaying could overwrite an existing decaying model belonging to another organisation in place, altering its name, formula, parameters, or ownership. - A user could create or modify a model flagged as the organisation default, affecting scoring behaviour for other users. - A user could reassign a model's organisation to an arbitrary value. Preconditions: - Authenticated user with decaying-model permission (perm_decaying). - Network access to the MISP instance. Affected: <2.5.48.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline