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CVE-2026-42248: Ollama Security Vulnerability (CVSS 7.7)

CVE-2026-42248 is a high severity security vulnerability in Ollama with a CVSS score of 7.7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-42248 is a high severity security vulnerability in Ollama with a CVSS score of 7.7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
7.7HIGH
EPSS probability
0.72%
Higher than 53 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:A)Adjacent network
Attack complexity (AC:L)Low complexity
Attack requirements (AT:P)Attack requirements present
Privileges required (PR:N)No privileges required
User interaction (UI:N)No user interaction
Confidentiality (VC:H)High confidentiality impact
Integrity (VI:H)High integrity impact
Availability (VA:H)High availability impact

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

CVE-2026-42248 affects Ollama, a product from Ollama. Before acting, confirm where Ollama 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: Ollama for Windows does not perform integrity or authenticity verification of downloaded update executables. Unlike other platforms, the Windows implementation of the update verification routine unconditionally returns success so no digital signature or trust validation is performed before staging or executing update payloads, enabling attacker‑supplied executables to be accepted and later executed by the application. Critically, Ollama for Windows performs silent automatic updates, so the malicious payload may be installed automatically without user awareness. Maintainers of this project were notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Versions from 0.12.10 to 0.17.5 were tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

Based on its CVSS vector, the flaw needs local or adjacent access, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductOllama
Affected versionsOllama from 0.12.10 up to and including 0.17.5
PublishedApr 29, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAcvd@cert.pl

How to detect it

  • Inventory every instance of Ollama 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 Ollama 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 Ollama 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-2026-42248 is a high severity security vulnerability in Ollama with a CVSS score of 7.7. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Related CVEs

HIGH7.7
CVE-2026-42249
Ollama

Ollama for Windows contains a Remote Code Execution vulnerability in its update mechanism due to improper handling of attacker‑controlled HTTP response headers. When downloading updates, the application constructs local file paths using values derived from HTTP headers without validation. These values are passed directly to filepath.Join, allowing path traversal sequences (../) to be resolved and enabling files to be written outside the intended update staging directory. An attacker who can influence update responses can exploit this flaw to write arbitrary executables to attacker‑chosen locations accessible to the current user, including the Windows Startup directory. This allows execution of arbitrary executables. Critically, when chained with CVE‑2026‑42248 (Missing Signature Verification for Updates), an attacker can deliver malicious payloads that are written to sensitive locations and executed automatically. Because Ollama for Windows performs silent automatic updates and executes staged binaries without user interaction, this results in automatic and persistent code execution without user awareness. Maintainers of this project were notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Versions from 0.12.10 to 0.17.5 were tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

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Mar 20, 2026
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Gradle

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Jan 16, 2026
All Ollama CVEs in 2026
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