CVE-2026-90955: MISP CLI Shell Audit Logs Lose User Identity and CLI Marker After First Lazy Model Load

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?

0.2%

EPSS score, percentile 5.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

4.6 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

The fix introduces a process-wide static identity (setShellUser) on SysLogLogableBehavior that is resolved at write time rather than at setup time … 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 2.5.46

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 introduces a process-wide static identity (setShellUser) on SysLogLogableBehavior that is resolved at write time rather than at setup time, so it survives lazy model loads that re-run setup() on the singleton. The behavior appends 'via CLI' to the log description for shell-originated rows, mirroring the request_type = CLI marker in the new audit engine. The CLI shell now publishes the impersonated user through both Configure::write('CurrentUserId') and SysLogLogableBehavior::setShellUser() before any write. Explicit extralog calls were added for CLI user edit, disable, and delete operations so the default audit engine records them the same way the web path does. Background jobs that publish no user continue to log as SYSTEM without a CLI marker.

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

Affected versions of MISP’s interactive CLI shell do not reliably preserve the identity of the impersonated MISP user across audit logging. The shell is designed to run actions as a supplied MISP user ID. However, the legacy SysLogLogable behavior stored that identity in behavior-instance state that could be overwritten when another model lazily attached the shared behavior. Consequently, subse…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-90955 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 14 Sep 2026.
• The CVE record carries a CVSS v4.0 base score of 4.6 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 5.1), 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 CLI Shell Audit Logs Lose User Identity and CLI Marker After First Lazy Model Load

Affected versions of MISP’s interactive CLI shell do not reliably preserve the identity of the impersonated MISP user across audit logging. The shell is designed to run actions as a supplied MISP user ID. However, the legacy SysLogLogable behavior stored that identity in behavior-instance state that could be overwritten when another model lazily attached the shared behavior. Consequently, subsequent CLI writes could lose the intended user attribution and be logged incorrectly. The commit also notes that CLI-originated records lacked a CLI marker, making them appear similar to ordinary web actions by that user. Version affected: ≤2.5.45

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

Timeline