CVE-2026-42248
Published: 29 April 2026
Summary
CVE-2026-42248 is a high-severity Download of Code Without Integrity Check (CWE-494) vulnerability in Ollama Ollama. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Compromise Software Supply Chain (T1195.002); ranked at the 29.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as NLP and Transformers; in the Supply Chain and Deployment risk domain.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26210
- 🇵🇱 CERT-PL: cert.pl
Vulnerability details
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…
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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.
- CWE(s)
AI Security AnalysisAI
- AI Category
- NLP and Transformers
- Risk Domain
- Supply Chain and Deployment
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: ollama
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is a client-side failure to verify update executable integrity/authenticity (CWE-494), directly enabling an attacker to supply and have the application silently execute a malicious payload via the automatic update mechanism.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Policies can require integrity verification of software prior to installation, reducing risks from unverified downloads.
Blocks installation of components lacking a valid signature, mitigating download or installation of code without integrity checks.
Acquisition and maintenance portions of the strategy drive requirements for integrity verification of downloaded or supplied code.
Mandating integrity control and approved-only changes during development prevents incorporation of code or components lacking integrity validation.
Supply chain protection requires integrity verification of acquired components, directly reducing insertion or tampering of malicious code during delivery.
Reduces exposure to code obtained without integrity verification by requiring assurance processes that confirm authenticity and absence of tampering.
Tamper resistance and detection commonly include integrity verification of code and firmware obtained from external sources.
Component authenticity requires verifying origin/integrity of acquired firmware or software, directly preventing inclusion of code without integrity checks.