CVE-2026-87997
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/open_webui/main.py copied a client-supplied folder_id into a new chat without applying the folder write-access check used by the dedicated chat routes. An authenticated user who knew a shared folder identifier could inject an attacker-controlled chat into a folder where the user had read-only or no write access, causing the entry to appear to authorized folder readers. This issue is fixed in version 0.11.1.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- Base score: 4.3
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.37%
- Percentile among all scored CVEs: 29
- Score date: 10/5/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
CWEs
- CWE-639, CWE-862
References
- https://github.com/open-webui/open-webui/commit/d9e23b90c100d19b00270aea3cde0501d2354a6c
- https://github.com/open-webui/open-webui/pull/28366
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1
- https://github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28
- https://github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28
Raw JSON (NVD)
Show
{
"id": "CVE-2026-87997",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-87997",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-14T13:43:57.477520Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 4.3,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 2.8
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "open-webui",
"product": "open-webui",
"versions": [
{
"status": "affected",
"version": ">= 0.10.0, < 0.11.1"
}
]
}
]
}
],
"published": "2026-09-09T22:18:48.267",
"references": [
{
"url": "https://github.com/open-webui/open-webui/commit/d9e23b90c100d19b00270aea3cde0501d2354a6c",
"tags": [
"Patch"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/open-webui/open-webui/pull/28366",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1",
"tags": [
"Release Notes"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28",
"tags": [
"Exploit",
"Vendor Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28",
"tags": [
"Exploit",
"Vendor Advisory"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-639"
},
{
"lang": "en",
"value": "CWE-862"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/open_webui/main.py copied a client-supplied folder_id into a new chat without applying the folder write-access check used by the dedicated chat routes. An authenticated user who knew a shared folder identifier could inject an attacker-controlled chat into a folder where the user had read-only or no write access, causing the entry to appear to authorized folder readers. This issue is fixed in version 0.11.1."
}
],
"lastModified": "2026-09-16T15:14:39.770",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9FA5514D-3F5D-4716-B12A-45ABA81E74DE",
"versionEndExcluding": "0.11.1",
"versionStartIncluding": "0.10.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}