CVE-2026-70486

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, the terminal file-preview serveUrl iframe branch always granted allow-same-origin together with allow-scripts for HTML files served from the application origin. Any authenticated user with access to a configured terminal server could cause script in a previewed file to run in the Open WebUI origin, read the victim's session token from localStorage, and take over the account, with possible server-side code execution if the victim was an admin or held workspace.functions. This issue is fixed in 0.11.0.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

August 4, 2026

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Aug 4, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_commit, github_release, github.
github_release Patch Available

v0.11.0

Patch available: open-webui/open-webui v0.11.0

https://github.com/open-webui/open-webui/releases/tag/v0.11.0
github_commit

commit 65a5fad7b97d (open-webui/open-webui)

Fix landed in open-webui/open-webui commit 65a5fad7b97d — awaiting tagged release

https://github.com/open-webui/open-webui/commit/65a5fad7b97db99d490d81f4e0860282c3a4543c
github_pr

fix: gate allow-same-origin on the terminal file-preview iframe to prevent same-origin XSS

Fix merged in open-webui/open-webui PR #26907 on 2026-07-10 — awaiting tagged release

https://github.com/open-webui/open-webui/pull/26907
github Patch Available🟡 PoC Available

Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin · Advisory · open-webui/open-webui · GitHub

Affected: 0.11.0 by

https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5

Vendor Advisories for CVE-2026-70486(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
open-webui0.10.0 ... 0.9.6 (10 versions)0.11.0—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 16× in last 7d / 38× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-20 23:28 UTCEG score recompute
  2. 2026-08-20 22:56 UTCEPSS rescore
  3. 2026-08-20 01:17 UTCEG score recompute
  4. 2026-08-19 17:04 UTCEPSS rescore
  5. 2026-08-18 15:48 UTCEG score recompute
  6. 2026-08-18 13:49 UTCEPSS rescore
  7. 2026-08-18 13:49 UTCEPSS rescore
  8. 2026-08-17 16:03 UTCEG score recompute
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-16 17:51 UTCEG score recompute
  11. 2026-08-16 14:56 UTCEPSS rescore
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 06:44 UTCEG score recompute
  14. 2026-08-16 02:15 UTCEPSS rescore
  15. 2026-08-15 08:33 UTCEG score recompute
  16. 2026-08-15 01:31 UTCEPSS rescore
  17. 2026-08-13 23:15 UTCEG score recompute
  18. 2026-08-13 22:00 UTCEPSS rescore
  19. 2026-08-12 13:57 UTCEG score recompute
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-11 15:45 UTCEG score recompute
  22. 2026-08-11 04:39 UTCEG score recompute
  23. 2026-08-11 00:00 UTCEPSS rescore
  24. 2026-08-09 19:22 UTCEG score recompute
  25. 2026-08-09 13:47 UTCEPSS rescore
Show 13 more
  1. 2026-08-08 21:10 UTCEG score recompute
  2. 2026-08-08 16:37 UTCEPSS rescore
  3. 2026-08-07 22:58 UTCEG score recompute
  4. 2026-08-07 00:46 UTCEG score recompute
  5. 2026-08-06 13:47 UTCEPSS rescore
  6. 2026-08-06 02:35 UTCEG score recompute
  7. 2026-08-05 19:17 UTCEPSS rescore
  8. 2026-08-05 19:17 UTCEPSS rescore
  9. 2026-08-05 15:29 UTCEG score recompute
  10. 2026-08-05 14:37 UTCEG score recompute
  11. 2026-08-04 20:31 UTCEG score recompute
  12. 2026-08-04 20:06 UTCEG score recompute
  13. 2026-08-04 20:06 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-70486?
CVE-2026-70486 is a high vulnerability published on August 4, 2026. Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, the terminal file-preview serveUrl iframe branch always granted allow-same-origin together with allow-scripts for HTML files served from the application origin. Any authenticated user with…
When was CVE-2026-70486 disclosed?
CVE-2026-70486 was first published in the National Vulnerability Database on August 4, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-70486 actively exploited?
CVE-2026-70486 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 69.2% of all scored CVEs.
What is the CVSS score of CVE-2026-70486?
CVE-2026-70486 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-70486?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-70486, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-70486

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