CVE-2026-9136: A vulnerability was identified in the ShadowAttribute proposal creation workflow.

A vulnerability was identified in the ShadowAttribute proposal creation workflow.

A vulnerability was identified in the ShadowAttribute proposal creation workflow. The add action accepted user-controlled ShadowAttribute request data without removing the id field before saving the record. Because the underlying framework treats a supplied primary key as an instruction to update an existing record, an authenticated user able to submit shadow attribute proposals could provide the identifier of an existing ShadowAttribute and cause that record to be updated instead of creating a new proposal. This can result in unauthorized modification of existing shadow attributes, potentially affecting proposals associated with events the user should not be able to alter. Depending on deployment configuration and accessible API responses, the issue may also expose or move proposal data across event contexts. The vulnerability is caused by trusting a client-supplied primary key during object creation. The fix removes the id field from incoming ShadowAttribute data before processing, ensuring that the endpoint always creates a new proposal rather than updating an existing one. This has been fixed in MISP 2.5.38.

Description from the National Vulnerability Database, published by 5a6e4751-2f3f-4070-9419-94fb35b644e8

What it means for a small business

If your business uses misp, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.23%, higher than 13% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

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Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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