CVE-2026-108711

EUVD-2026-96985
Plastic Labs Honcho through 3.3.0 contains an incorrect authorization vulnerability that allows peer- or session-scoped API key holders to read workspace data because get_or_create_workspace checks only the workspace claim. Attackers can submit their parent workspace name to the POST /v3/workspaces endpoint to retrieve workspace metadata and configuration, including custom_instructions, reserved for workspace or admin keys.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 18.6%
Common Weakness Enumeration
References
https://github.com/plastic-labs/honcho
https://github.com/plastic-labs/honcho/blob/608aec8a928da13c540262ed980c569448fb53ab/src/crud/workspace.py#L112-L119
https://github.com/plastic-labs/honcho/blob/608aec8a928da13c540262ed980c569448fb53ab/src/routers/workspaces.py#L41-L72
https://github.com/plastic-labs/honcho/blob/608aec8a928da13c540262ed980c569448fb53ab/src/security.py#L218-L225
https://hackmd.io/@haind/honcho-scoped-jwt-workspace-config-disclosure
https://www.vulncheck.com/advisories/plastic-labs-honcho-through-3.3.0-incorrect-authorization-via-post-v3-workspaces