CVE-2026-45396

MEDIUM
Published May 15, 2026 Modified May 19, 2026 CWE-915

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses model_config = ConfigDict(extra='allow'). Due to an insecure dictionary merge order in insert_new_feedback(), an authenticated attacker can inject a user_id field in the request body that overwrites the server-derived value, creating feedback records attributed to any arbitrary user. This corrupts the model evaluation leaderboard (Elo ratings) and enables identity spoofing. This vulnerability is fixed in 0.9.5.

Is your site exposed to CVE-2026-45396?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.4
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0004
Probability of exploitation
0.14%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-915 CWE-915

Affected Products

Vendor Product
openwebui open_webui

References

Frequently Asked Questions

What is CVE-2026-45396? +
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses model_config = ConfigDict(extra='allow'). Due to an insecure dictionary merge order in insert_new_feedback(), an authenticated attacker can inject a user_id field in the request body that overwrites the server-derived value, creating feedback records attributed to any arbitrary user. This corrupts the model evaluation leaderboard (Elo ratings) and enables identity spoofing. This vulnerability is fixed in 0.9.5. It has a CVSS v3.1 base score of 5.4 (MEDIUM).
How severe is CVE-2026-45396? +
CVE-2026-45396 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-45396? +
CVE-2026-45396 affects products from openwebui, specifically: open_webui. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-45396? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-24370

Django-Unicorn adds modern reactive component functionality to Django templates. Affected versions of Django-Unicorn are vulnerable to python class pollution vulnerability. …
CVE-2025-2304

A Privilege Escalation through a Mass Assignment exists in Camaleon CMS When a user wishes to change his password, the …
CVE-2026-15083

Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in Drupal ECA: Event - Condition - Action allows Object Injection. This …
CVE-2025-58367

DeepDiff is a project focused on Deep Difference and search of any Python data. Versions 5.0.0 through 8.6.0 are vulnerable …
CVE-2025-9315

An unauthenticated device registration vulnerability, caused by Improperly Controlled Modification of Dynamically-Determined Object Attributes, has been identified in the MXsecurity …
CVE-2026-45058

electerm is an open-sourced terminal/ssh/sftp/telnet/serialport/RDP/VNC/Spice/ftp client. In 3.8.8 and earlier, there is persistent local-pty code execution via imported bookmarks or …

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2026-45396 — free, no signup required.