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Fencer Vulns
high 7.5

CVE-2025-66959 json

An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoder

published 2026-01-21 9 mo ago modified 2026-06-17 4 mo ago also PYSEC-2026-101 , EUVD-2026-3626

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
5.3%
EPSS 5.3% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

An issue in ollama v.0.12.10 allows a remote attacker to cause a denial of service via the GGUF decoder

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-66959 updated cvss 7.5

ollama: ollama: Denial of Service via GGUF decoder

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-trustyai-ragas-lls-provider-dsp-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform/ee-minimal-rhel9, ansible-automation-platform-26/mcp-tools-rhel9, ansible-automation-platform-24/de-minimal-rhel8, ansible-automation-platform-24/de-minimal-rhel9, ansible-automation-platform-24/ee-minimal-rhel8, +28 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

5.33% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/ollama/ollama/issues/9820 referenced PoC, tagged "exploit" by a source, unverified
  • zero.shotlearni.ng https://zero.shotlearni.ng/blog/cve-2025-66959panic-dos-via-unchecked-length-in-gguf-decoder-copy/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-20 Improper Input Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.