How severe is CVE-2026-87994?

CVE-2026-87994 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-87994 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-87994?

CVE-2026-87994 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-87994?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-87994 published?

CVE-2026-87994 was published on 2026-09-09 and last updated on 2026-09-16.

CVE-2026-87994

CVE-2026-87994 is a medium-severity vulnerability in Openwebui Open Webui with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-639
Affected product: Openwebui Open Webui
Published: 2026-09-09
Last modified: 2026-09-16

Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in backend/open_webui/main.py checked channel write access and channel membership for a supplied message_id but did not verify that the calling user authored the targeted message. A channel member could use the chat completions endpoint to replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. This issue is fixed in version 0.11.1.

Frequently asked questions

What is CVE-2026-87994?: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in backend/open_webui/main.py checked channel write access and channel membership for a supplied message_id but did not verify that the calling user authored the targeted message. A channel member could use the chat completions endpoint to replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. This issue is fixed in version 0.11.1.
How severe is CVE-2026-87994?: CVE-2026-87994 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-87994 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-87994?: CVE-2026-87994 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-87994?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-87994 published?: CVE-2026-87994 was published on 2026-09-09 and last updated on 2026-09-16.

References

Affected products (1)

cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*

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