Livebook Teams identity callback lacks state binding, allowing login CSRF

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-66885
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-05 20:17:13 UTC
Updated2026-08-05 20:17:13 UTC
DescriptionCross-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.

Risk And Classification

Primary CVSS: v4.0 6.8 MEDIUM from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-352 | CWE-352 CWE-352 Cross-Site Request Forgery (CSRF)

VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary6.8MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS6.8MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
Active
Confidentiality
High
Integrity
None
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Livebook-dev Livebook affected 0.15.0 0.18.7 semver Not specified
CNA Livebook-dev Livebook affected 0.19.0 0.19.9 semver Not specified
CNA Livebook-dev Livebook affected 0.15.0 0.18.7 other Not specified
CNA Livebook-dev Livebook affected 0.19.0 0.19.9 other Not specified
CNA Livebook-dev Livebook affected 0.15.0-cuda12 0.18.7-cuda12 other Not specified
CNA Livebook-dev Livebook affected 0.19.0-cuda12 0.19.9-cuda12 other Not specified
CNA Livebook-dev Livebook affected 4380a411920531223088267ed1c0ad21f96ef660 * git Not specified

References

ReferenceSourceLinkTags
osv.dev/vulnerability/EEF-CVE-2026-66885 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/livebook-dev/livebook/security/advisories/GHSA-pvvw-28fw-c6fg 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/livebook-dev/livebook/commit/6ed2e213e9d5a19a70d7fcad5a8d6166... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/livebook-dev/livebook/commit/33a052daa386c4ce08a9c39a07fc90f3... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/livebook-dev/livebook/commit/21c16168263275541a6e076d0c31852c... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
cna.erlef.org/cves/CVE-2026-66885.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Nguyễn Công Tú (en)

CNA: Jonatan Kłosko (en)

CNA: José Valim (en)

CNA: Hugo Baraúna (en)

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