CVE-2026-86408: MISP Missing Authorization in Cryptographic Key View Exposes Signing Keys from Protected Events

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 27.5 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?

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

Advisories and patches (1)

Which versions are affected?

Affected

• 2.5.45 and earlier

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

Advisories and patches

• github.com (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.

Versions not listed are: unaffected.

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

About this vulnerability

Affected versions of MISP do not enforce parent-event visibility when serving cryptographic keys through CryptographicKeysController::view(). The vulnerable handler queried CryptographicKey directly using the supplied key ID and selected sensitive fields such as: * type * key_data * fingerprint but did not fetch or authorize the associated parent event first. The upstr…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-86408 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 7 Sep 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 27.5), 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 Missing Authorization in Cryptographic Key View Exposes Signing Keys from Protected Events

Affected versions of MISP do not enforce parent-event visibility when serving cryptographic keys through CryptographicKeysController::view(). The vulnerable handler queried CryptographicKey directly using the supplied key ID and selected sensitive fields such as: * type * key_data * fingerprint but did not fetch or authorize the associated parent event first. The upstream commit explicitly states that cryptographicKeys/view could return a protected event’s signing key to any authenticated user. The fix adds parent_id and parent_type to the lookup and then enforces authorization through the associated event using fetchSimpleEvent($user, parent_id). If the parent is not an Event, access is limited to site administrators. Version affected: ≤2.5.45

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

Timeline