PatchSiren cyber security CVE debrief

CVE-2026-10855 misp CVE debrief

An authorization flaw existed in the MISP Event Template Importer overwrite workflow. When importing an event template in overwrite mode, the application checked whether a matching template already existed but did not verify that the importing user belonged to the organization that owned the existing template. As a result, an authenticated user with access to the template import functionality could forcibly overwrite an event template owned by another organization.

Vendor: misp
Product: Unknown
CVSS: MEDIUM 5.1
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-04
Original CVE updated: 2026-07-22
Advisory published: 2026-06-04
Advisory updated: 2026-07-22

Who should care

Site administrators and users with access to the template import functionality in MISP installations.

Technical summary

The issue was fixed by enforcing an ownership check before overwrite: non-site-admin users may only overwrite templates owned by their own organization.

Defensive priority

MEDIUM

Recommended defensive actions

Apply the patch: https://github.com/MISP/MISP/commit/7c2200d143bef86aaf58d701b6968a843097db69 (ref-4)

Evidence notes

The CVSS score for this vulnerability is 5.1 (MEDIUM).

Sources and references

Verified primary and authoritative sources

CVE-2026-10855 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-10855

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-10855 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-10855

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Mitigation or vendor reference
Unverified legacy reference

URL: https://github.com/MISP/MISP/commit/7c2200d143bef86aaf58d701b6968a843097db69

5a6e4751-2f3f-4070-9419-94fb35b644e8 - Patch

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.