CVE-2026-54397

MEDIUMCVSS 6.1/10EPSS 0.23%

Last modified

CVE-2026-54397 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the submitted form data and set an event’s sharing_group_id to a sharing group they were not authorized to use. When distribution was set to sharing group distribution, the non-REST save path accepted the submitted sharing_group_id without performing the same sharing group authorization check enforced by the REST edit path. An attacker could exploit this by tampering with the event edit request and assigning an event to an undisclosed or unauthorized sharing group. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the submitted form data and set an event’s sharing_group_id to a sharing group they were not authorized to use. When distribution was set to sharing group distribution, the non-REST save path accepted the submitted sharing_group_id without performing the same sharing group authorization check enforced by the REST edit path. An attacker could exploit this by tampering with the event edit request and assigning an event to an undisclosed or unauthorized sharing group. This could result in unauthorized use of restricted sharing groups, disclosure of the sharing group name in event listings, and unintended modification of the event’s distribution metadata. The issue is fixed by validating that the selected sharing group can be used by the current user when the sharing group is changed, and by clearing sharing_group_id when the event distribution is not set to sharing group distribution.

Metrics

CVSS 4.0
6.1/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:H/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

EPSS Probability
0.23%

13.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-54397?
A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the submitted form data and set an event’s sharing_group_id to a sharing group they were not authorized to use. When distribution was set to sharing group distribution, the non-REST save path accepted the submitted sharing_group_id without performing the same sharing group authorization check enforced by the REST edit path. An attacker could exploit this by tampering with the event edit request and assigning an event to an undisclosed or unauthorized sharing group. This could result in unauthorized use of restricted sharing groups, disclosure of the sharing group name in event listings, and unintended modification of the event’s distribution metadata. The issue is fixed by validating that the selected sharing group can be used by the current user when the sharing group is changed, and by clearing sharing_group_id when the event distribution is not set to sharing group distribution.
How severe is CVE-2026-54397?
CVE-2026-54397 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.
How do I fix CVE-2026-54397?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-54397?

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Source: NVD / NIST