MISP Missing Authorization in Cryptographic Key View Exposes Signing Keys from Protected Events

published 2026-09-07 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-72358

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits: 0; none known

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

Patch / fix

links 1

github.com/MISP/MISP@2edde61 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-09-08)

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.1	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
CNA	4.0	7.1	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
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

MISP MISP

Classification

Weakness

CWE-862 Missing Authorization
CWE-639 Authorization Bypass Through User-Controlled Key

References

github.com /MISP/MISP/commit/2edde619b
patch

Sources

CVE List CVE-2026-86408
NVD CVE-2026-86408

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary