CVE-2026-87997

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 88% 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
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: 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 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/open_webui/main.py copied a client-supplied folder_id into a new chat without applying the folder write-access check used by the dedicated chat routes. An authenticated user who knew a shared folder identifier could inject an attacker-controlled chat into a folder where the user had read-only or no write access, causing the entry to appear to authorized folder readers. This issue is fixed in version 0.11.1.

CVSS v3
4.3
EG Score
4.3(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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
Severity43% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 16, 2026

Advisory Details (4)

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

commit d9e23b90c100 (open-webui/open-webui)

Fix landed in open-webui/open-webui commit d9e23b90c100 — awaiting tagged release

https://github.com/open-webui/open-webui/commit/d9e23b90c100d19b00270aea3cde0501d2354a6c
github_pr

refac: share one folder write-access check across chat folder_id paths

Fix merged in open-webui/open-webui PR #28366 on 2026-08-11 — awaiting tagged release

https://github.com/open-webui/open-webui/pull/28366
github Patch Available🟡 PoC Available

Any authenticated user can inject chats into another user's folder via chat completions · Advisory · open-webui/open-webui · GitHub

Affected: 0.11.1 by

https://github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28

Vendor Advisories for CVE-2026-87997(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, 0.10.1, 0.10.2, 0.11.00.11.1—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 21× 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. 2026-09-18 21:22 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:14 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-16 15:30 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 15:39 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-14 14:30 UTCEG score recompute
  11. 2026-09-14 13:50 UTCEG score recompute
  12. 2026-09-13 18:25 UTCEG score recompute
  13. 2026-09-13 16:48 UTCEPSS rescore
  14. 2026-09-12 17:16 UTCEG score recompute
  15. 2026-09-12 15:02 UTCEPSS rescore
  16. 2026-09-11 16:07 UTCEG score recompute
  17. 2026-09-11 14:53 UTCEPSS rescore
  18. 2026-09-11 14:53 UTCEPSS rescore
  19. 2026-09-09 22:31 UTCEG score recompute
  20. 2026-09-09 21:41 UTCEG score recompute
  21. 2026-09-09 21:40 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87997?
CVE-2026-87997 is a medium vulnerability published on September 9, 2026. Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/openwebui/main.py copied a client-supplied folderid into a new chat without applying the folder write-access check…
When was CVE-2026-87997 disclosed?
CVE-2026-87997 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87997 actively exploited?
CVE-2026-87997 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 87.6% of all scored CVEs.
What is the CVSS score of CVE-2026-87997?
CVE-2026-87997 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-87997?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87997, 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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