CVE-2026-104910: MISP Information Disclosure via Related Events Listing Bypassing Per-Event Authorization

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 20.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.3 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

The fix enforces proper per-event authorization on the related events query by applying the user's full access-control conditions (including published status … 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 fix enforces proper per-event authorization on the related events query by applying the user's full access-control conditions (including published status, distribution level, and sharing group membership) to the event lookup, rather than relying solely on the stale distribution snapshot stored in the correlation table. This ensures that only events the caller is currently permitted to read are returned in the related events list.

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 authorization bypass in the related events listing functionality. When a user requests the list of events correlated to a given event, the system retrieved related event metadata directly from the correlation table without re-validating the caller's access rights against each related event. The correlation table stores a snapshot of the event's distribution level and sharing gro…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-104910 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 5.3 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 20.1), 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 Information Disclosure via Related Events Listing Bypassing Per-Event Authorization

MISP contains an authorization bypass in the related events listing functionality. When a user requests the list of events correlated to a given event, the system retrieved related event metadata directly from the correlation table without re-validating the caller's access rights against each related event. The correlation table stores a snapshot of the event's distribution level and sharing group at the time the correlation was created, and does not carry the published flag. As a result, events that the caller is not permitted to open—because they are unpublished, or because their distribution or sharing group has changed since the correlation was recorded—were still returned with their metadata (title, date, correlating value counts). Preconditions: - An authenticated user with access to at least one event in MISP. - The existence of correlation entries linking that event to other events the user should not be able to view. Impact: - Unauthorized disclosure of event metadata (titles, dates, correlation counts) for events the user has no right to access. - Potential reconnaissance of threat-intelligence event names and timelines across sharing groups. Affected: MISP versions prior to the fix commit (2ffa97f05).

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

Timeline