CVE WatchOct 23, 2026

CVE-2026-109299

Open WebUI from 0.9.0 before 0.11.4 contains a denial of service vulnerability that allows authenticated users with automations permission t

CVSS

6.5

Medium

EPSS

0.4%

p30

KEV

—

Exploit Today

0-100

Published: Oct 12, 2026 · Last modified: Oct 23, 2026 · CWE-400 · CWE-834

EPSS · 30d

0.4%EPSS · 30 days0.4%

2026-10-132026-10-23

Technical description

Open WebUI from 0.9.0 before 0.11.4 contains a denial of service vulnerability that allows authenticated users with automations permission to stall the instance by submitting unsatisfiable recurrence rules. Attackers can repeatedly send rules like February 30th to the automations create or update endpoints, blocking the shared event loop for seconds per request.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-1157787.5 HIG

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———Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.mail.imap4.IMAP4Server reaches twisted.mail.imap4.parseNestedParens with a negative literal size in an authenticated SEARCH command after the client enters the selected mailbox state. The negative size moves the parser cursor below zero, and Python's negative indexing prevents the synchronous scanning loop from terminating. The loop freezes the single-threaded reactor, stopping other IMAP connections and any SMTP or POP3 services hosted in the same process until restart. This issue is fixed in version 26.10.0rc1.9h CVE-2026-115585—

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———pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an incomplete remediation for repeated malformed cross-reference entries in GHSA-55h5-xmcq-c37v could still trigger a complete PDF stream reload during each recovery attempt even when a recovery cache was present, causing crafted cross-reference streams to produce long runtimes. This issue is fixed in version 6.21.2.10h CVE-2026-115580—

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———pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an attacker can craft a PDF with a standard cross-reference table whose declared entry count exceeds what the file can contain, causing excessive processing and long runtimes when the file is opened. This issue is fixed in version 6.21.2.10h