Server hang via cyclic chat deletion
Published Sep 9, 2026 · Updated Sep 9, 2026
Denial of service in Open WebUI 0.10.0 through 0.11.0 allows remote authenticated users to hang the server via message deletion. The deletion helper follows attacker-controlled childrenIds without recording visited messages, so a cyclic chat tree makes the synchronous request loop run forever. Any default-role account can store the cycle and trigger it against its own chat, blocking all requests until the process is killed.
Summary
What happened
Denial of service in Open WebUI 0.10.0 through 0.11.0 allows remote authenticated users to hang the server via message deletion. The deletion helper follows attacker-controlled childrenIds without recording visited messages, so a cyclic chat tree makes the synchronous request loop run forever. Any default-role account can store the cycle and trigger it against its own chat, blocking all requests until the process is killed.
The record
- CVE
- CVE-2026-88000
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- Open WebUI
- Product
- Open WebUI
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.10.0, < 0.11.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Vendor advisory cyclic-chat proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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