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Fencer Vulns
high 8.7

CVE-2026-103235 json

MISP Event Delegation Mass Assignment Allows Retargeting Delegation to Arbitrary Events

published 2026-09-30 40 d ago modified 2026-09-30 40 d ago also EUVD-2026-89728

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

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

Patch / fix

  • MISP MISP 2.5.48

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
40 d ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/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

Affected products

  • MISP MISP

Classification

Weakness
  • CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

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.