Information Disclosure in Cinnamon (CVE-2026-86867)
Summary
Vulnerability in Cinnamon (CVE-2026-86867). Data can be tampered with by attackers. Exploitable via user_id.
Original description
The description as published by the source.
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:
- Read other user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions.
- Permanently delete another user's conversation.
- Rename another user's conversation.
- Overwrite another user's conversation's chat suggestion list.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-86867 has been found in Cinnamon.
Attackers can target a specific entry point like user_id over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Cinnamon CVE-2026-86867" on the vendor's site.
CVE-2026-86867 (Cinnamon) — CWE-200 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: user_id / Conversation.user
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in Cinnamon. Attackers reach the vulnerable code path via user_id.
Check the vendor advisory for the affected versions of Cinnamon. Attack surface: user_id / Conversation.user.
Severity: Medium (CVSS 6.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Cinnamon' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Cinnamon' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Cinnamonを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web kb.cert.org
- web kb.cert.org
- web nvd.nist.gov
- web github.com