MISP Event Delegation Mass Assignment Allows Retargeting Delegation to Arbitrary Events (CVE-2026-103235) | HOL Guard CVE

High · CVSS 8.7CVE-2026-103235

MISP Event Delegation Mass Assignment Allows Retargeting Delegation to Arbitrary Events

Answer in brief

CVE-2026-103235 records a High severity (CVSS 8.7) vulnerability in MISP Event Delegation Mass Assignment Allows Retargeting Delegation to Arbitrary Events. The current sources do not mark it as known exploited. The current feed maps MISP/MISP (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 30, 2026Updated Sep 30, 2026Source checked Sep 30, 2026First seen by HOL Sep 30, 2026Material review Sep 30, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps MISP/MISP (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
MISP/MISPgeneric	>=0 <2.5.48	2.5.48

Recommended response

Check inventory. Check lockfiles and deployed manifests for MISP/MISP.
Review the reported fix. Source-reported solution: The delegation record is now constructed from a strict allow-list of fields rather than persisting the raw user-submitted payload. The event_id is always derived from the authorized event in the URL, the requester_org_id is always taken from the authenticated session, and the primary key is never included in the saved data. Only message, distribution, and sharing_group_id are accepted from user input, eliminating the ability to retarget or overwrite existing delegation records.

Evidence timeline and material changes

Published upstream
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 30, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

MISP contains a mass assignment vulnerability in the event delegation feature. When a user with delegation permission submits a delegation request, the application authorized the user against the event identified in the URL but then persisted the entire submitted record, including caller-supplied fields such as the primary key and event_id. An authenticated attacker could inject a primary key or event_id into the delegation payload to retarget an existing delegation record to any event on the instance. Because a delegation row grants the requesting organisation read access to the event it references, this effectively granted read access to arbitrary events belonging to other organisations. If the target organisation subsequently accepted the delegation, ownership of the event was transferred and the original record was deleted. Preconditions: - An authenticated user with the delegation permission (perm_delegate) - The MISP.delegation server setting must be enabled Impact: - Confidentiality: read access to any event on the instance - Integrity: overwriting existing delegation records and transferring event ownership Affected versions: MISP < 2.5.48

Quoted source text, attributed separately from HOL analysis.