CVE-2026-87015

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% 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
Elevated
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: Elevated riskExposed: 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 0.6.27 until 0.11.1, backend/open_webui/utils/tools.py captured a cookie jar from the enclosing connection loop instead of binding it to each external tool callable. When multiple tool servers were attached and a session or system OAuth connection was processed last, a request to a different server configured for bearer authentication could include the calling user's Open WebUI session cookies, allowing that server's operator to reuse the session and take over the account. This issue is fixed in version 0.11.1.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
47(Track*)
EG Risk 47/100SSVC: 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
Severity68% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 15, 2026

Advisory Details (4)

Auto-updated Sep 9, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available🟡 PoC Available

A user's session cookies are sent to tool servers configured for bearer authentication · Advisory · open-webui/open-webui · GitHub

Affected: 0.11.1 by

https://github.com/open-webui/open-webui/security/advisories/GHSA-p78m-89r6-pgf7
github_release Patch Available

v0.11.1

Patch available: open-webui/open-webui v0.11.1

https://github.com/open-webui/open-webui/releases/tag/v0.11.1
github_pr

refac: bind tool server cookies per connection

Fix merged in open-webui/open-webui PR #28630 on 2026-08-17 — awaiting tagged release

https://github.com/open-webui/open-webui/pull/28630
github_commit

commit cd9db21c5276 (open-webui/open-webui)

Fix landed in open-webui/open-webui commit cd9db21c5276 — awaiting tagged release

https://github.com/open-webui/open-webui/commit/cd9db21c5276807a2975ddba17cef369ad1114b7

Vendor Advisories for CVE-2026-87015(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 (44 versions)0.11.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 22× 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. 2026-09-19 09:45 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 11:11 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-16 14:27 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 06:00 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-14 07:48 UTCEG score recompute
  12. 2026-09-13 09:35 UTCEG score recompute
  13. 2026-09-12 11:23 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 13:11 UTCEG score recompute
  17. 2026-09-10 14:59 UTCEG score recompute
  18. 2026-09-10 14:21 UTCEG score recompute
  19. 2026-09-10 14:00 UTCEG score recompute
  20. 2026-09-09 21:30 UTCEG score recompute
  21. 2026-09-09 21:15 UTCEG score recompute
  22. 2026-09-09 21:14 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87015?
CVE-2026-87015 is a medium vulnerability published on September 9, 2026. Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.6.27 until 0.11.1, backend/open_webui/utils/tools.py captured a cookie jar from the enclosing connection loop instead of binding it to each external tool callable. When multiple tool servers were attached…
When was CVE-2026-87015 disclosed?
CVE-2026-87015 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87015 actively exploited?
CVE-2026-87015 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 78.5% of all scored CVEs.
What is the CVSS score of CVE-2026-87015?
CVE-2026-87015 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-87015?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87015, 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

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