Summary
Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids)
Impact
Message integrity destruction: an authenticated user can overwrite a message in a channel they cannot access, regardless of membership. The overwritten message retains the original author attribution while displaying attacker-chosen content (impersonation). Private channels, DM channels, and channels the attacker has no access to are all affected; the REST channel routes correctly return 403 for the same attacker, so the bypass is specific to the chat-completion channel pipeline.
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-59714 has a CVSS score of 7.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.10.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Validate every value in message_ids against the channel (not just the first), rejecting any whose target message does not belong to the channel in chat_id. Additionally, make _make_channel_emitter fail closed: re-check that the target message's channel_id matches the channel before calling Messages.update_message_by_id, treating a missing or mismatched message as an error/no-op.
Frequently Asked Questions
- What is CVE-2026-59714? CVE-2026-59714 is a high-severity missing authorization vulnerability in open-webui (pip), affecting versions >= 0.9.5, < 0.10.0. It is fixed in 0.10.0. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-59714? CVE-2026-59714 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of open-webui are affected by CVE-2026-59714? open-webui (pip) versions >= 0.9.5, < 0.10.0 is affected.
- Is there a fix for CVE-2026-59714? Yes. CVE-2026-59714 is fixed in 0.10.0. Upgrade to this version or later.
- Is CVE-2026-59714 exploitable, and should I be worried? Whether CVE-2026-59714 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-59714 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-59714? Upgrade
open-webuito 0.10.0 or later.