CVE-2026-10855Network attack vector

Cross-organization template overwrite via missing ownership check

Published Jun 4, 2026 · Updated Jun 4, 2026

Missing authorization in MISP 2.5.38 and earlier allows remote authenticated users to overwrite event templates owned by other organizations. EventTemplateImporter::import reused a matched template ID in overwrite mode without comparing the importing user’s organization to the template owner. Access to authenticated template import was sufficient; the overwrite could alter another organization’s template structure, attributes, or metadata.

CVSS severity5.1
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in MISP 2.5.38 and earlier allows remote authenticated users to overwrite event templates owned by other organizations. EventTemplateImporter::import reused a matched template ID in overwrite mode without comparing the importing user’s organization to the template owner. Access to authenticated template import was sufficient; the overwrite could alter another organization’s template structure, attributes, or metadata.

The record

CVE
CVE-2026-10855
Published
Jun 4, 2026
Updated
Jun 4, 2026
Vendor
MISP Project
Product
MISP
Classifications
CWE-862, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.5.38

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MISP Project · MISPversion=0 <=2.5.38

Published CVSS scores

5.1CIRCLCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
4.3NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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