Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
open-webui open-webui — Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L L N U N N H 6.5 .0037 30.5 —
AFFECTED
Product Versions Fixed
open-webui >= 0.9.2, < 0.10.0 – —
TIMELINE
Jul 2 Reserved by GitHub_M
Jul 9 EXPLOIT PUBLISHED — CVE-2026-59220 (open-webui). Public exploit reference added.
Jul 9 Published (CNA: GitHub_M)
Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.2 before 0.10.0, the SKILL_MENTION_RE and strip_re regular expressions in backend/open_webui/utils/middleware.py parsed <$skillId|label> skill mentions with overlapping quantifiers, allowing an authenticated chat message containing <$ without a closing > to trigger quadratic backtracking and block the asyncio event loop. This issue is fixed in version 0.10.0.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 2, 2026 | Reserved | Reserved by GitHub_M |
| July 9, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-59220 (open-webui). Public exploit reference added. |
| July 9, 2026 | Published | Published (CNA: GitHub_M) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| open-webui | open-webui | — | >= 0.9.2, < 0.10.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-59220 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.