CVE-2026-45339

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 77% 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, nvd
Elevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

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

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely — the request is authenticated, the model is invoked, and a full response is returned. This vulnerability is fixed in 0.9.0.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
22.8%
KEV
Not listed

Published

May 15, 2026

Last Modified

May 19, 2026

Advisory Details (1)

Auto-updated May 18, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints · Advisory · open-webui/open-webui · GitHub

https://github.com/open-webui/open-webui/security/advisories/GHSA-57q6-fvp4-pqmm

Vendor Advisories for CVE-2026-45339(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-webu—0.9.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 34× 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. 2026-07-16 17:03 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-13 22:30 UTCEPSS rescore
  5. 2026-07-13 06:13 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-08 15:16 UTCEPSS rescore
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-06 16:27 UTCEPSS rescore
  12. 2026-07-06 02:23 UTCEPSS rescore
  13. 2026-07-05 02:30 UTCEPSS rescore
  14. 2026-07-01 15:07 UTCEPSS rescore
  15. 2026-06-30 23:22 UTCEPSS rescore
  16. 2026-06-29 14:06 UTCEPSS rescore
  17. 2026-06-29 14:06 UTCEPSS rescore
  18. 2026-06-28 14:07 UTCEPSS rescore
  19. 2026-06-28 04:56 UTCEPSS rescore
  20. 2026-06-28 04:56 UTCEPSS rescore
  21. 2026-06-27 03:08 UTCEPSS rescore
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-24 14:05 UTCEPSS rescore
  24. 2026-06-23 21:33 UTCEPSS rescore
  25. 2026-06-23 21:33 UTCEPSS rescore
Show 47 more
  1. 2026-06-22 14:25 UTCEPSS rescore
  2. 2026-06-22 14:25 UTCEPSS rescore
  3. 2026-06-21 14:56 UTCEPSS rescore
  4. 2026-06-21 14:56 UTCEPSS rescore
  5. 2026-06-21 01:59 UTCEPSS rescore
  6. 2026-06-19 19:25 UTCEPSS rescore
  7. 2026-06-18 17:52 UTCEPSS rescore
  8. 2026-06-18 17:52 UTCEPSS rescore
  9. 2026-06-17 17:53 UTCEPSS rescore
  10. 2026-06-16 17:52 UTCEPSS rescore
  11. 2026-06-15 17:49 UTCEPSS rescore
  12. 2026-06-12 23:12 UTCEPSS rescore
  13. 2026-06-12 23:12 UTCEPSS rescore
  14. 2026-06-11 14:00 UTCEPSS rescore
  15. 2026-06-10 22:18 UTCEPSS rescore
  16. 2026-06-10 13:22 UTCEPSS rescore
  17. 2026-06-10 13:22 UTCEPSS rescore
  18. 2026-06-08 14:17 UTCEPSS rescore
  19. 2026-06-08 14:17 UTCEPSS rescore
  20. 2026-06-07 15:25 UTCEPSS rescore
  21. 2026-06-07 15:25 UTCEPSS rescore
  22. 2026-06-06 13:47 UTCEPSS rescore
  23. 2026-06-06 13:47 UTCEPSS rescore
  24. 2026-06-05 22:47 UTCEPSS rescore
  25. 2026-06-05 06:10 UTCEPSS rescore
  26. 2026-06-05 06:10 UTCEPSS rescore
  27. 2026-06-04 13:12 UTCEPSS rescore
  28. 2026-06-04 13:12 UTCEPSS rescore
  29. 2026-06-02 20:13 UTCEPSS rescore
  30. 2026-06-01 13:52 UTCEPSS rescore
  31. 2026-06-01 13:52 UTCEPSS rescore
  32. 2026-05-31 22:30 UTCEPSS rescore
  33. 2026-05-31 22:30 UTCEPSS rescore
  34. 2026-05-31 00:16 UTCEPSS rescore
  35. 2026-05-31 00:16 UTCEPSS rescore
  36. 2026-05-29 13:44 UTCEPSS rescore
  37. 2026-05-29 13:44 UTCEPSS rescore
  38. 2026-05-28 13:44 UTCEPSS rescore
  39. 2026-05-28 13:44 UTCEPSS rescore
  40. 2026-05-27 13:40 UTCEPSS rescore
  41. 2026-05-27 13:40 UTCEPSS rescore
  42. 2026-05-26 13:44 UTCEPSS rescore
  43. 2026-05-26 07:18 UTCEPSS rescore
  44. 2026-05-21 22:43 UTCEPSS rescore
  45. 2026-05-20 22:38 UTCEPSS rescore
  46. 2026-05-20 11:59 UTCEG score recompute
  47. 2026-05-20 11:22 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-45339?
CVE-2026-45339 is a medium vulnerability published on May 15, 2026. Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-...…
When was CVE-2026-45339 disclosed?
CVE-2026-45339 was first published in the National Vulnerability Database on May 15, 2026, with the most recent update on May 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45339 actively exploited?
CVE-2026-45339 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45339?
CVE-2026-45339 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-45339?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45339, 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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