CVE-2025-66959: Ollama Denial of Service via GGUF Decoder
Ollama
A denial of service vulnerability affects Ollama version 0.12.10 through its GGUF decoder implementation. Remote attackers can exploit the flaw to disrupt service.
disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why
- CVSS
- 7.5
- EPSS
- 0.05 · top 8% · 2026-11-13
- fix status
- Fix status unknown
- first report
- 21 Jan 2026
- last update
- 21 Jan 2026
- CVE ids
Timeline · 1
Sources · 1
Advisories and databases
- 2026-01-21CVE-2025-66959: An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoderNVD · nvd.nist.gov/vuln/detail/CVE-2025-66959
Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.
Classification
- lane
- Patch now
- AI role
- Attack on AI
- categories
- Infrastructure vulnerability
- severity
- 2 · Disclosed vulnerability
- fix status
- Fix status unknown
- targets
- Framework / tooling
- owasp llm top 10
- LLM03:2025 Supply Chain
- mitre atlas
- no technique for these categories
- dates
- happened 21 Jan 2026 · first reported 21 Jan 2026
- origin
- NVDVulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
- record
- confidence 0.95 · created 2026-10-18 10:04Z · updated 2026-10-18 10:04Z
Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned
Copy a brief
This record as a short Markdown brief, for a ticket, a chat or a coding agent.
the brief as text
# CVE-2025-66959: Ollama Denial of Service via GGUF Decoder https://gcdradar.vercel.app/incidents/cve-2025-66959-ollama-denial-of-service-via-gguf-decoder · AIR-2026-0945 · closed 2026-01-21 - Lane: Patch now - Severity: 2 (Disclosed vulnerability) - Fix status: Fix status unknown - First reported: 2026-01-21 - AI role: Attack on AI - Products: Ollama - CVE ids: CVE-2025-66959 - CVSS: 7.5 ## Summary A denial of service vulnerability affects Ollama version 0.12.10 through its GGUF decoder implementation. Remote attackers can exploit the flaw to disrupt service. ## What to do No action recorded; read the sources below and the vendor's advisory. ## Latest updates - 2026-01-21: CVE-2025-66959: An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoder (https://nvd.nist.gov/vuln/detail/CVE-2025-66959) ## Sources - 2026-01-21 NVD: CVE-2025-66959: An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoder https://nvd.nist.gov/vuln/detail/CVE-2025-66959 Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.
Related
- closed7.5Ollama CVE-2025-66960: Ollama Denial of Service via GGUF Metadata
Patch now · Disclosed · since 21 Jan 2026 · CVE-2025-66960
AI - closed8.7Ollama CVE-2025-15514: Ollama null pointer dereference in image processing
Patch now · Disclosed · since 12 Jan 2026 · CVE-2025-15514
AI - closed7.5Ollama CVE-2026-15685: Ollama downloadBlob Denial-of-Service Vulnerability
Patch now · Disclosed · since 13 Jul 2026 · CVE-2026-15685
AI - closed7.5Ollama CVE-2026-5757: Ollama model quantization engine information disclosure vulnerability
Patch now · Disclosed · since 26 Jun 2026 · CVE-2026-5757
AI - closed6.3Open WebUI CVE-2026-54021: Open WebUI proxy bypass routes calls to arbitrary Ollama backends
Patch now · Disclosed · since 17 Jun 2026 · updated 23 Jun 2026 · CVE-2026-54021
AI - closed5.4Open WebUI CVE-2026-44563: Open WebUI Ollama Model Access Control Bypass
Patch now · Disclosed · since 8 May 2026 · updated 15 May 2026 · CVE-2026-44563
AI