CVE-2025-1975: Github.com/ollama/ollama Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-wrh5-cmwx-q2qr
Share
CVSS 7.5
CWE-129
Published
Advisory Summary

CVE-2025-1975 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-129: Improper Validation of Array Index) affecting Github.com/ollama/ollama libraries in the Go ecosystem. The issue involves ollama server vulnerable to denial of service (dos) attack. Remediation is available in the latest vendor maintenance releases.

CVE-2025-1975 at a Glance

CVE Identifier CVE-2025-1975
GHSA Identifier GHSA-wrh5-cmwx-q2qr
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-129: Improper Validation of Array Index
Affected Product Github.com/ollama/ollama
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2025-1975

To remediate this vulnerability, upgrade all affected Github.com/ollama/ollama dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/ollama/ollama fixed: Latest secure release 
Upgrade github.com/ollama/ollama to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/ollama/ollama

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-1975, inspect your project dependencies for Github.com/ollama/ollama:

inspect dependencies for github.com/ollama/ollama

Analyze the terminal output to locate any version of Github.com/ollama/ollama in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-129: Improper Validation of Array Index, where the product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. In Github.com/ollama/ollama, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability in the Ollama server version 0.5.11 allows a malicious user to cause a Denial of Service (DoS) attack by customizing the manifest content and spoofing a service. This is due to improper validation of array index access when downloading a model via the /api/pull endpoint, which can lead to a server crash.

CVE-2025-1975 Affected Github.com/ollama/ollama Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/ollama/ollama
golang/github.com/ollama/ollama
Go
≤ 0.5.11

References

NVD — CVE-2025-1975 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-1975
Github.com/ollama/ollama Source Repository REPOSITORY
https://github.com/ollama/ollama
Github.com/ollama/ollama Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/ollama/PYSEC-2025-145.yaml
huntr.com/bounties/921ba5d4-f... WEB
https://huntr.com/bounties/921ba5d4-f1d0-4c66-9764-4f72dffe7acd
pkg.go.dev/vuln/go-2025-3695 WEB
https://pkg.go.dev/vuln/GO-2025-3695

Frequently Asked Questions

What is CVE-2025-1975?
CVE-2025-1975 is a security vulnerability in Github.com/ollama/ollama involving Ollama Server Vulnerable to Denial of Service (DoS) Attack under CWE-129: Improper Validation of Array Index.
Which Github.com/ollama/ollama versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/ollama/ollama.
What version fixes CVE-2025-1975?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/ollama/ollama affected?
Yes, github.com/ollama/ollama is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2025-1975?
CVE-2025-1975 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-1975?
CVE-2025-1975 is classified under CWE-129: Improper Validation of Array Index (The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.).
How can I check Go dependencies for CVE-2025-1975?
Run the dependency tree command: 'inspect dependencies for github.com/ollama/ollama'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wrh5-cmwx-q2qr",
  "modified" : "2026-06-06T01:02:21Z",
  "published" : "2025-05-16T09:30:36Z",
  "aliases" : [ "CVE-2025-1975" ],
  "summary" : "Ollama Server Vulnerable to Denial of Service (DoS) Attack",
  "details" : "A vulnerability in the Ollama server version 0.5.11 allows a malicious user to cause a Denial of Service (DoS) attack by customizing the manifest content and spoofing a service. This is due to improper validation of array index access when downloading a model via the /api/pull endpoint, which can lead to a server crash.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/ollama/ollama"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.5.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-1975"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ollama/ollama"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/ollama/PYSEC-2025-145.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.com/bounties/921ba5d4-f1d0-4c66-9764-4f72dffe7acd"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2025-3695"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-129" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-05-17T15:10:13Z",
    "nvd_published_at" : "2025-05-16T09:15:17Z"
  }
}