CVE-2026-66298
Untrusted notebook JS can trigger Livebook shortcuts to force eval, restart, or delete cells.
Is CVE-2026-66298 being exploited?
Not confirmed. CVE-2026-66298 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.17% probability of exploitation in the next 30 days.
How severe is CVE-2026-66298?
CVE-2026-66298 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-66298?
Yes. A fix has been recorded for CVE-2026-66298. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-66298 affect?
CVE-2026-66298 affects Livebook >=0.5.0 and <0.18.7, Livebook >=0.19.0 and <0.19.9. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-66298?
Upgrade Livebook to >=0.18.7 or >=0.19.9; avoid opening untrusted notebooks.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Untrusted notebook JavaScript can synthesize key events to force full notebook evaluation, restart runtimes (loss of in-memory state), or delete cells, enabling code execution on the runtime.
Immediate action required
- affected>= 0.5.0 and < 0.18.7
- affected>= 0.19.0 and < 0.19.9
- affected>= 0.5.0-cuda12 and < 0.18.7-cuda12
- affected>= 0.19.0-cuda12 and < 0.19.9-cuda12
- affected>= 844242ba80a928d0d675416d312a58003cb7771b and < *
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.