Skip to content
Heist/ feed
Back to feed
High

Missing Signature Verification for Updates in Ollama

Type: advisorySources: OSV

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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-42248
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 17:30 UTC · Revision 1

Source evidence

Missing Signature Verification for Updates in Ollama

core-osv · Original source

Published 29 Apr 2026, 11:44 UTC

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.

osv:CVE-2026-42248
Complete source record
{
  "id": "9116ef2ae157d9608d0ebd169652165bbf4053356a278718e30dd0f9db18947e",
  "url": "https://osv.dev/vulnerability/CVE-2026-42248",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Missing Signature Verification for Updates in Ollama",
    "summary": "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.",
    "evidence": "osv:CVE-2026-42248",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-42248",
      "aliases": [
        "CVE-2026-42248"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ollama/ollama",
              "type": "GIT",
              "events": [
                {
                  "introduced": "80d34260ea16e76c9ef0d014a86cc130421855f1"
                },
                {
                  "last_affected": "86513cb697c9842265863b03ba1e916b959a63c0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.12.10"
                      },
                      {
                        "last_affected": "0.17.5"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:ollama:ollama:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.12.10"
                      },
                      {
                        "last_affected": "0.17.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.17.5",
            "v0.17.4",
            "v0.17.3",
            "v0.17.2",
            "v0.17.1",
            "v0.17.1-rc2",
            "v0.17.1-rc1",
            "v0.17.1-rc0",
            "v0.17.0-rc2",
            "v0.17.0",
            "v0.17.0-rc1",
            "v0.17.0-rc0",
            "v0.16.3-rc2",
            "v0.16.3",
            "v0.16.3-rc1",
            "v0.16.3-rc0",
            "v0.16.2-rc0",
            "v0.16.2",
            "v0.16.1",
            "v0.16.0-rc2",
            "v0.16.0",
            "v0.16.0-rc1",
            "v0.16.0-rc0",
            "v0.15.6",
            "v0.15.5",
            "v0.15.5-rc5",
            "v0.15.5-rc4",
            "v0.15.5-rc3",
            "v0.15.5-rc1",
            "v0.15.5-rc2",
            "v0.15.5-rc0",
            "v0.15.4",
            "v0.15.3",
            "v0.15.1",
            "v0.15.2",
            "v0.15.1-rc1",
            "v0.15.1-rc0",
            "v0.15.0-rc6",
            "v0.15.0",
            "v0.15.0-rc5",
            "v0.15.0-rc4",
            "v0.15.0-rc3",
            "v0.15.0-rc2",
            "v0.15.0-rc1",
            "v0.15.0-rc0",
            "v0.14.3",
            "v0.14.3-rc3",
            "v0.14.3-rc2",
            "v0.14.0-rc10",
            "v0.14.3-rc1",
            "v0.14.3-rc0",
            "v0.14.2",
            "v0.14.2-rc1",
            "v0.14.2-rc0",
            "v0.14.1",
            "v0.14.0-rc11",
            "v0.14.0",
            "v0.14.0-rc9",
            "v0.14.0-rc8",
            "v0.14.0-rc7",
            "v0.14.0-rc6",
            "v0.14.0-rc5",
            "v0.14.0-rc4",
            "v0.14.0-rc3",
            "v0.14.0-rc2",
            "v0.14.0-rc1",
            "v0.14.0-rc0",
            "v0.13.5-rc1",
            "v0.13.5",
            "v0.13.5-rc0",
            "v0.13.4-rc2",
            "v0.13.4",
            "v0.13.4-rc1",
            "v0.13.4-rc0",
            "v0.13.3",
            "v0.13.3-rc1",
            "v0.13.3-rc0",
            "v0.13.2",
            "v0.13.2-rc2",
            "v0.13.2-rc1",
            "v0.13.2-rc0",
            "v0.13.1",
            "v0.13.1-rc2",
            "v0.13.1-rc1",
            "v0.13.1-rc0",
            "v0.13.0-rc0",
            "v0.13.0",
            "v0.12.11",
            "v0.12.11-rc1",
            "v0.12.11-rc0",
            "v0.12.10-rc1",
            "v0.12.10"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42248.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.385626536Z",
      "provider": "osv",
      "references": [
        "https://ollama.com/",
        "https://cert.pl/en/posts/2026/04/CVE-2026-42248/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42248.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-42248",
        "https://github.com/ollama/ollama"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-494"
        ],
        "cna_assigner": "CERT-PL",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42248.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-42248",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 487762,
  "published_at": "2026-04-29T11:44:33.77+00:00"
}