CVE-2026-86867

Cinnamon's Kotaemon (all versions up to and including v0.12.0) multi-user chat interface contains multiple vulnerabilities due to incorrect authorization and improper access controls. There are four handler methods in `libs/ktem/ktem/pages/chat/control.py` that load a Conversation record by its ID without comparing the requester's `user_id` to the conversation's owner `Conversation.user`. This allows any authenticated user to perform the following actions: 1. Read other user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions. 2. Permanently delete another user's conversation. 3. Rename another user's conversation. 4. Overwrite another user's conversation's chat suggestion list.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://kb.cert.org/vuls/id/754548
https://www.kb.cert.org/vuls/id/754548

Configurations

No configuration.

History

24 Sep 2026, 15:17

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.5
CWE		CWE-639 CWE-200 CWE-862

23 Sep 2026, 19:19

Type	Values Removed	Values Added
References		() https://www.kb.cert.org/vuls/id/754548 -

23 Sep 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-23 18:17

Updated : 2026-09-24 15:17

NVD link : CVE-2026-86867

Mitre link : CVE-2026-86867

CVE.ORG link : CVE-2026-86867

JSON object : View

Products Affected

No product.

CWE

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

CWE-639

Authorization Bypass Through User-Controlled Key

CWE-862

Missing Authorization

{"id": "CVE-2026-86867", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-86867", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-24T14:37:13.797147Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.8}]}, "affected": [{"source": "cret@cert.org", "affectedData": [{"vendor": "Cinnamon AI", "product": "Kotaemon", "versions": [{"status": "affected", "version": "0.12.0"}]}]}], "published": "2026-09-23T18:17:09.323", "references": [{"url": "https://kb.cert.org/vuls/id/754548", "source": "cret@cert.org"}, {"url": "https://www.kb.cert.org/vuls/id/754548", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-639"}, {"lang": "en", "value": "CWE-862"}]}], "descriptions": [{"lang": "en", "value": "Cinnamon's Kotaemon (all versions up to and including v0.12.0) multi-user chat interface contains multiple vulnerabilities due to incorrect authorization and improper access controls. There are four handler methods in `libs/ktem/ktem/pages/chat/control.py` that load a Conversation record by its ID without comparing the requester's `user_id` to the conversation's owner `Conversation.user`. This allows any authenticated user to perform the following actions:\r\n1. Read other user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions.\r\n2. Permanently delete another user's conversation.\r\n3. Rename another user's conversation.\r\n4. Overwrite another user's conversation's chat suggestion list."}], "lastModified": "2026-09-24T15:17:49.290", "sourceIdentifier": "cret@cert.org"}