CyberSecBulletin
CVE-2026-66297NVD status: Modified

livebook: Improper Neutralization of Special Elements used in an OS Command

Published Updated By the CyberSecBulletin desk

CVE-2026-66297 is a high-severity improper neutralization of special elements used in an OS command vulnerability in livebook from Livebook-dev, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists versions 0.18.7, 0.19.9, 0.18.7-cuda12 as the first without the flaw, so updating livebook to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.47% chance of exploitation within 30 days, higher than 85% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update livebook to 0.18.7 or 0.19.9 or 0.18.7-cuda12 or 0.19.9-cuda12, whichever matches your release line, or a later version.
  2. Read the advisory on cna.erlef.org for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Livebook-devlivebook0.13.0 up to, but not including, 0.18.7; 0.19.0 up to, but not including, 0.19.9; 0.13.0-cuda12 up to, but not including, 0.18.7-cuda12; 0.19.0-cuda12 up to, but not including, 0.19.9-cuda12; 7cf4af5c10ec645f55a10f30e5661c54f6a6b319 and later0.18.7, 0.19.9, 0.18.7-cuda12, 0.19.9-cuda12

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.05.0MediumCNA
CVSS 3.18.0HighNVD

Official description

Improper Neutralization of Special Elements used in an OS Command (OS Command Injection) vulnerability in livebook-dev livebook allows command injection into generated deployment setup commands. LivebookWeb.Hub.Teams.DeploymentGroupAgentComponent.docker_instructions/2 and LivebookWeb.Hub.Teams.DeploymentGroupAgentComponent.fly_instructions/4 in lib/livebook_web/live/hub/teams/deployment_group_agent_component.ex interpolate deployment group environment variable values into the generated Docker and Fly.io setup commands without shell escaping. The values originate from the deployment group configuration and reach the sinks through Livebook.Hubs.Dockerfile.online_docker_info/3. Both sinks place the value inside a double-quoted shell word, so a value containing a command substitution such as $(...) or backticks is evaluated by the shell without any need to break out of the quoting, and a literal double quote terminates the quoted word and allows arbitrary further tokens. The generated command is displayed in the Livebook web interface with a copy button, so a user who copies it and runs it without reviewing it first executes the injected commands on their own machine, under their own account. An attacker requires privileges sufficient to set deployment group environment variables, while the resulting code execution occurs on the machine of whoever runs the generated command. The Kubernetes instructions are not affected, because they render the same values into a YAML manifest with escaping rather than into a shell command. This issue affects livebook: from 0.13.0 before 0.18.7 and from 0.19.0 before 0.19.9.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in livebook

All livebook vulnerabilities

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

Spotted an error? Tell us.