CVE-2025-66959: ollama Improper Input Validation
CVSS: 7.5v3.1HighAnalyzed
AliasesPYSEC-2026-101
Published 21-01-2026Last modified 22-01-2026
Vulnerability summary
CVE-2025-66959 is a high (CVSS 7.5) Improper Input Validation vulnerability in ollama. EPSS estimates a 5.33% chance of exploitation in the next 30 days, higher than 92.5% of scored vulnerabilities. 2 public exploits are recorded.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
5.33%
0%100%
Low · +0.12 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits2github, reference
Timeline
- 21-01-2026PublishedVulnerability first disclosed.
- 22-01-2026Last modifiedVulnerability information updated.
Description
An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoder
CVSS metrics
3 scores · 3 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesAll 3 agree
- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
5.33%
Chance of exploitation in the next 30 days
Percentile
93%
Versus all other CVEs
30-day change
+0.12 pp
From 5.21% on 18-09-2026
18-09-202618-10-2026
EPSS score5.33%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
2 foundOllama
Maturity: poc
Exploit Reference (zero.shotlearni.ng)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
Affected systems
Ollama1 product
- ollama0.12.10
PyPI1 product
- ollama≤ 0.12.10-NA
2 vendors · 2 products
References
2 links- zero.shotlearni.ng/blog/cve-2025-66959panic-dos-via-unchecked-length-in-gguf-decoder-copy/EVIDENCEExploitThird Party Advisory