Auth bypass in Misp

CVE-2026-86408

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

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (26.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86408: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86408?
CVE-2026-86408 is a medium-severity vulnerability in Misp, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-09-07.
How severe is CVE-2026-86408?
Medium severity. CVSS v3 base score is 6.5 out of 10.