> CVE-2026-87994 [MEDIUM]

« BACK_TO_HOME
PUBLISHED
2026-09-09 22:18
MODIFIED
2026-09-09 22:18
CVSS_SCORE V3
4.3
EPSS (Prob. Exploit)
0.37%
Top 70.0%
DATA SOURCES:
NVD 🔗 2026-09-09 CWE MITRE 🔗 2026-10-01 FIRST EPSS 🔗 2026-10-25 GITHUB 🔗 2026-09-14 OSV 🔗 2026-09-21

> DESCRIPTION

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in backend/open_webui/main.py checked channel write access and channel membership for a supplied message_id but did not verify that the calling user authored the targeted message. A channel member could use the chat completions endpoint to replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. This issue is fixed in version 0.11.1.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EXPLOITABILITY
2.8
IMPACT
1.4

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
Low (L)
Authentifié avec compte utilisateur basique
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
Low (L)
Modification limitée des données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
Low
Modification limitée des données possible
Disponibilité
None
Aucune interruption de service

> WEAKNESSES

CWE-639 CWE-862

> CWE DETAILED DESCRIPTIONS

CWE-639: Authorization Bypass Through User-Controlled Key - The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. | CWE-862: Missing Authorization - The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

> GITHUB SECURITY ADVISORY

GHSA-fmqh-xp37-5hr8 MODERATE

Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint

AFFECTED PACKAGES:
PIP / open-webui
>= 0.9.5, < 0.11.1
Fixed in: 0.11.1

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint

AFFECTED PACKAGES:
Unknown / Unknown
5 versions affected
ALIASES:
GHSA-fmqh-xp37-5hr8

> HISTORIQUE DES MODIFICATIONS

Première apparition
09/09/2026 22:18
Source: NVD
📊 ENRICHISSEMENT 01/10/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-639: Authorization Bypass Through User-Controlled Key - The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key...
Total des modifications: 1 Dernière mise à jour: 3 weeks ago

> REFERENCES

https://github.com/open-webui/open-webui/commit/7d392bedc9c1aaecc94509a58e59186b...
https://github.com/open-webui/open-webui/pull/28631
https://github.com/open-webui/open-webui/releases/tag/v0.11.1
https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8
« BACK_TO_HOME