What is CVE-2026-87998?

CVE-2026-87998 is Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion. The supplied enrichment data classifies it as Privilege Esc mapped to CWE-269 Improper Privilege Management; CWE-863 Incorrect Authorization.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-87998. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-87998 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-87998. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-87998 using CVSS 7.1, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highPrivilege Esc

CVE-2026-87998

CVE-2026-87998 — Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, DELETE /api/v1/knowledge/{id}/delete in backend/open_webui/routers/knowledge.py authorized deletion against the knowledge base but then removed its administrator-owned external connection without a separate administrator check or a check for other dependent knowledge bases. A non-administrator with write access to one external knowledge base could delete shared instance configuration and make every other knowledge base using that connection unavailable. This issue is fixed in version 0.11.1.

Published Sep 9, 2026Updated Sep 9, 2026Sources: NVD, open-webui (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

open-webui

CVSS base

7.1

high

Remediation

The vendor's own words where we have them.

Upgrade open-webui to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
open-webui	open-webui	>= 0.10.0, < 0.11.1	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

Low

Confidentiality

None

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

Low

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7.1	CVSS 3.1	high	2.8	4.2	GitHub (CNA), open-webui (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-863 · Incorrect Authorization

Read Application Data
Read Files or Directories
Modify Application Data
Modify Files or Directories

Mitigation: Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.

CWE-269 · Improper Privilege Management

Gain Privileges or Assume Identity::

Mitigation: Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.

Weakness & attack patterns

CWE-269Improper Privilege Management
CWE-863Incorrect Authorization

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-122 · Privilege AbuseCAPEC-58 · Restful Privilege ElevationCAPEC-233 · Privilege Escalation

T1548Abuse Elevation Control Mechanism

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /api/v1/knowledge/, /delete, /open_webui/routers/knowledge.py.
Prioritize edge telemetry for network-reachable open-webui.
Review endpoint telemetry for service binary replacement, suspicious service launches, or privilege changes tied to the affected agent.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 7.1 (AV:N)
Sep 9, 2026 · NVD
Initial · CVE published
Sep 9, 2026 · NVD
CVE published by MITRE.
Sep 9, 2026 · SOCRadar CTI

References

4 on the record

github.com/open-webui/open-webui/commit/dc03e7e595d61be97b25a1dd7bb99ad264f73199
Exploit, Third Party Advisory, Mitre
github.com/open-webui/open-webui/pull/28113
Exploit, Third Party Advisory, Mitre
github.com/open-webui/open-webui/releases/tag/v0.11.1
Exploit, Third Party Advisory, Mitre
github.com/open-webui/open-webui/security/advisories/GHSA-2724-6cpj-gf3v
Exploit, Third Party Advisory, Mitre

Elsewhere on this site

open-webuievery CVE for this vendor
Privilege Escsame class
CWE-269other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-87998 is Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion, a high vulnerability affecting open-webui from open-webui. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-87998. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-87998. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.1 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.