CVE-2026-56400

CRITICALNVD 9.69.6
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.6 under NVD CVSS v3. EPSS exploit probability: 0.5% (42nd percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 8.3 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-07-15) is not newer than that change (2026-07-16), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this weekElevated
9.6EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.6Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.

CVSS v3
9.6
EG Score
9.6CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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 (value × EchelonGraph’s weight)
Severity96% × 45%
The EG Score, 9.6 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
42nd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 15, 2026

Last Modified

July 16, 2026

Advisory Details (2)

Auto-updated Oct 7, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

GitHub Security Lab (GHSL) Vulnerability Report, open-webui: GHSL-2024-174, GHSL-2024-175 · Advisory · open-webui/open-webui · GitHub

https://github.com/open-webui/open-webui/security/advisories/GHSA-6xcp-7mpr-m7wm
Web page

open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation | Advisories | VulnCheck

https://www.vulncheck.com/advisories/open-webui-remote-code-execution-via-cors-misconfiguration-and-session-validation

Vendor Advisories for CVE-2026-56400(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 rangeFix by version rangeDependents
open-webui0.1.124 ... 0.3.9 (51 versions)
  • every version up to 0.3.33: fixed in 0.3.33
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 50× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 360 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 260 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 01:54 UTCEG score recompute
  2. 2026-10-14 01:54 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-12 22:10 UTCEG score recompute
  5. 2026-10-12 22:10 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  7. 2026-10-12 15:54 UTCEG score recompute
  8. 2026-10-12 06:49 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  9. 2026-10-11 19:38 UTCEG score recompute
  10. 2026-10-11 16:53 UTCEG score recompute
  11. 2026-10-11 14:16 UTCEG score recompute
  12. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  15. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-10-01 12:42 UTCEG score recompute
  24. 2026-10-01 12:42 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  25. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
Show 75 more
  1. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-09-28 13:15 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  4. 2026-09-28 08:48 UTCEG score recompute
  5. 2026-09-28 08:48 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  6. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  7. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  9. 2026-09-24 13:20 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  10. 2026-09-24 08:55 UTCEG score recompute
  11. 2026-09-24 08:55 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  12. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-09-23 11:31 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  14. 2026-09-23 07:27 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  15. 2026-09-23 03:23 UTCEG score recompute
  16. 2026-09-23 03:23 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  17. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  18. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  19. 2026-09-18 09:59 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  20. 2026-09-18 04:47 UTCEG score recompute
  21. 2026-09-18 04:47 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  22. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  24. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  26. 2026-09-14 11:33 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  27. 2026-09-14 07:22 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  28. 2026-09-14 03:17 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  29. 2026-09-13 23:13 UTCEG score recompute
  30. 2026-09-13 23:13 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  31. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  32. 2026-09-13 16:25 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  33. 2026-09-13 11:49 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  34. 2026-09-13 07:17 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  35. 2026-09-12 17:09 UTCEG score recompute
  36. 2026-09-12 17:09 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  37. 2026-09-12 13:05 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  38. 2026-09-12 07:26 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  39. 2026-09-12 01:51 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  40. 2026-09-11 21:47 UTCEG score recompute
  41. 2026-09-11 21:47 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  42. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  43. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  44. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  45. 2026-09-08 00:58 UTCEG score recompute
  46. 2026-09-08 00:58 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  47. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  48. 2026-09-06 17:44 UTCEG score recompute
  49. 2026-09-06 17:44 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  50. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  51. 2026-09-06 13:29 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  52. 2026-09-06 01:30 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  53. 2026-09-05 20:52 UTCEG score recompute
  54. 2026-09-05 20:52 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  55. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  56. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  57. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  58. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  59. 2026-08-31 05:16 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  60. 2026-08-31 01:12 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  61. 2026-08-30 21:08 UTCEG score recompute
  62. 2026-08-30 21:08 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  63. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  64. 2026-08-30 17:04 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  65. 2026-08-30 13:00 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  66. 2026-08-30 08:00 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  67. 2026-08-30 03:56 UTCEG score recompute
  68. 2026-08-30 03:56 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  69. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  70. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  71. 2026-08-28 01:52 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  72. 2026-08-27 21:28 UTCEG score recompute
  73. 2026-08-27 21:28 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3
  74. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  75. 2026-08-27 12:44 UTCGHSA enrichmentGHSA-m5hr-9f92-qvh9 · GitHub severity CRITICAL · GitHub CVSS 8.3

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-56400?
CVE-2026-56400 is a critical-severity vulnerability; its CVE record was published on July 15, 2026. open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests…
When was CVE-2026-56400 made public?
CVE-2026-56400 was made public on May 5, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on July 15, 2026. EchelonGraph's copy of the record carries a last-modified date of July 16, 2026; the record at its source may have been updated since.
Is CVE-2026-56400 actively exploited?
CVE-2026-56400 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-56400?
CVE-2026-56400 has a CVSS v3 base score of 9.6 (NVD).
How do I remediate CVE-2026-56400?
A fix for CVE-2026-56400 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-56400 are linked in the Vendor Advisories panel on this page.

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