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CVE-2026-100846: Project-Monai Monai Deserialization of Untrusted Data (CVSS 8.8)

CVE-2026-100846 is a high severity deserialization of untrusted data in Project-Monai Monai with a CVSS score of 8.8. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Oct 8, 2026

Quick answer

Direct answer

CVE-2026-100846 is a high severity deserialization of untrusted data in Project-Monai Monai with a CVSS score of 8.8. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
8.8HIGH
EPSS probability
0.29%
Higher than 20 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:H)High complexity
Attack requirements (AT:P)Attack requirements present
Privileges required (PR:H)High privileges required
User interaction (UI:P)Passive user interaction
Confidentiality (VC:H)High confidentiality impact
Integrity (VI:H)High integrity impact
Availability (VA:H)High availability impact

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

About Project-Monai Monai

CVE-2026-100846 affects Project-Monai Monai, a product from Project-Monai. Before acting, confirm where Project-Monai Monai runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: MONAI before 1.5.2 contains a deserialization of untrusted data vulnerability in the algo_from_pickle function in monai/auto3dseg/utils.py. The function reads a .pkl file and passes its contents to pickle.loads without validating the data source or content. If an application invokes algo_from_pickle on an attacker-supplied pickle file, an object defining __reduce__ is executed during deserialization, resulting in arbitrary code execution in the context of the application.

The weakness class is Deserialization of Untrusted Data. The application rebuilds objects from attacker controlled data, which can run code.

Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and relies on a user taking an action. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductProject-Monai Monai
Affected versionsMonai before 1.5.2
PublishedSep 27, 2026
Last modifiedOct 8, 2026
Added to CISA KEVNot listed
Assigning CNAdisclosure@vulncheck.com

How to detect it

  • Inventory every instance of Project-Monai Monai and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Project-Monai Monai named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Project-Monai Monai to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-100846 is a high severity deserialization of untrusted data in Project-Monai Monai with a CVSS score of 8.8. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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