CVE-2026-66885

What it is

Cross-Site Request Forgery (CSRF) vulnerability in livebook-dev livebook allows an attacker to authenticate a victim's browser session under the attacker's own Livebook Teams identity. When Livebook is configured to use Livebook Teams for identity, Livebook.ZTA.LivebookTeams.handle_request/4 in lib/livebook/zta/livebook_teams.ex handles the OAuth-style callback carrying a teams_identity marker and a code parameter. The clause exchanges that code for an access token and writes the token into the browser session without verifying any value that ties the callback to the browser session that started the login. No state or nonce is generated when the flow is initiated: Livebook.Teams.Requests.create_auth_request/1 in lib/livebook/teams/requests.ex sends an empty request body, so no per-attempt value is ever registered, and the callback clause has nothing to compare against. An attacker who holds membership in the same Livebook Teams organisation as the target instance can therefore begin the login flow themselves, retain the resulting authorization code without redeeming it, and induce a victim to open a crafted URL carrying that code. The victim's browser completes the exchange and the resulting session is bound to the attacker's identity rather than the victim's. The victim is not required to hold any particular privilege, and no credential belonging to the victim is involved. The vulnerability does not allow the attacker to authenticate as the victim. The consequence is that a user believes they are working in their own authenticated session while they are in fact operating as another identity. Work performed in that session is attributed to the attacker's account, and secrets, uploaded data, or notebook results the victim produces are exposed to the attacker rather than kept in the victim's own account. The authorization code must be redeemed within a short window after the login flow begins, which constrains the timing of the attack but not its feasibility. This issue affects livebook: from 0.15.0 before 0.18.7 and from 0.19.0 before 0.19.9.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-05 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 16:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-08-05 20:17 UTC

Last modified

2026-10-24 16:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-352 · Cross-site request forgery

Record status

Analyzed

Affected

• Livebook < 0.18.7
• Livebook < 0.19.9

Attack profile CVSS 4.0 · 6.8

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

Active

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

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