CVE-2026-70481
Received Received - Intake

Unauthorized Message Modification in Open WebUI

Publication date: 2026-08-04

Last updated on: 2026-08-04

Assigner: GitHub, Inc.

Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.0, the standard channel message update and delete handlers accepted any caller holding write access on the channel without checking that the caller wrote the message. Because write access is the same grant a member needs to post, any ordinary participant in a shared standard channel could rewrite or permanently delete another participant message, while group and direct message handlers enforced authorship. This issue is fixed in 0.11.0.

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Meta Information

Published
2026-08-04
Last Modified
2026-08-04
Generated
2026-08-05
AI Q&A
2026-08-04
EPSS Evaluated
N/A
NVD
CVE-2026-70481
EUVD
EUVD-2026-52882

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
open_webui open_webui From 0.5.0 (inc) to 0.10.3 (exc)
open_webui open_webui 0.11.0
open_webui open_webui From 0.5.0 (inc) to 0.11.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-284 The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

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Executive Summary

This vulnerability in Open WebUI allowed any user with write access to a standard channel to edit or delete messages posted by other users. The system failed to verify message authorship for standard channels, unlike group or direct message channels where authorship checks were enforced. This could lead to unauthorized changes to message content while retaining the original author's attribution.

Detection Guidance

To detect this vulnerability, check if your Open WebUI instance is running a vulnerable version (0.5.0 to 0.10.2). Review message edit and delete logs in standard channels to identify unauthorized modifications or deletions by users without authorship. Look for discrepancies where a user's name is retained but the content was changed by another user.

Impact Analysis

If you use Open WebUI versions 0.5.0 to 0.10.2, an attacker with write access to a standard channel could modify or delete your messages, potentially altering content under your name or erasing important information. This could disrupt collaboration, spread misinformation, or cause data loss in shared channels.

Compliance Impact

This vulnerability could impact compliance with GDPR and HIPAA by allowing unauthorized users to modify or delete messages in standard channels without proper authorization. This may lead to tampering with records, compromising data integrity, and violating audit requirements that mandate non-repudiation and secure record-keeping.

Mitigation Strategies

Immediately upgrade Open WebUI to version 0.11.0 or later to apply the authorship enforcement fix. Review and audit message history in standard channels for unauthorized edits or deletions. Restrict write access to standard channels to trusted users only until the upgrade is complete.

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