CVE-2026-56398

CRITICALNVD 9.09.0
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.0 under NVD CVSS v3. EPSS exploit probability: 0.6% (49th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 7.3 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 week
9.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs. Authenticated users who visit the profile image endpoint receive attacker-controlled SVG content with inline disposition and no default security headers, enabling script execution in the same origin to steal authentication tokens and achieve account takeover.

CVSS v3
9.0
EG Score
9.0CRITICALmedium confidence
EG Risk
41
EG Risk 41/100

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)
Severity90% × 45%
The EG Score, 9.0 of 10.
Exploitation0.6% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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.
EPSS PROB
0.6%
EPSS %ILE
49th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 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 partial (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 Jul 15, 2026
Patch available. Sources: github.
Web page

Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI | Advisories | VulnCheck

https://www.vulncheck.com/advisories/open-webui-stored-cross-site-scripting-via-oauth-picture-claim-svg-data-uri
GitHub advisoryMentions a patch (unverified)

Stored XSS via OAuth picture claim stored as SVG data URI in profile_image_url · Advisory · open-webui/open-webui · GitHub

https://github.com/open-webui/open-webui/security/advisories/GHSA-3wgj-c2hg-vm6q

Vendor Advisories for CVE-2026-56398(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 ... 0.9.4 (156 versions)
  • every version up to 0.9.5: fixed in 0.9.5
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 51× 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 376 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 276 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-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  4. 2026-10-12 22:10 UTCEG score recompute
  5. 2026-10-12 22:10 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  7. 2026-10-12 15:54 UTCEG score recompute
  8. 2026-10-12 06:49 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  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 0.6% · 48th percentile
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  15. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  17. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  20. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  21. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  23. 2026-10-01 16:23 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  24. 2026-10-01 12:42 UTCEG score recompute
  25. 2026-10-01 12:42 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
Show 75 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  2. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  3. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  4. 2026-09-28 13:15 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  5. 2026-09-28 08:48 UTCEG score recompute
  6. 2026-09-28 08:48 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  8. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  9. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-09-24 13:20 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  11. 2026-09-24 08:55 UTCEG score recompute
  12. 2026-09-24 08:55 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  13. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  14. 2026-09-23 10:59 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  15. 2026-09-23 07:04 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  16. 2026-09-23 03:23 UTCEG score recompute
  17. 2026-09-23 03:23 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  18. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  19. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  20. 2026-09-18 09:59 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  21. 2026-09-18 04:47 UTCEG score recompute
  22. 2026-09-18 04:47 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  23. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  26. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  27. 2026-09-14 10:27 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  28. 2026-09-14 06:46 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  29. 2026-09-14 03:04 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  30. 2026-09-13 23:13 UTCEG score recompute
  31. 2026-09-13 23:13 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  32. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  33. 2026-09-13 16:25 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  34. 2026-09-13 11:49 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  35. 2026-09-13 07:17 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  36. 2026-09-12 16:46 UTCEG score recompute
  37. 2026-09-12 16:46 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  38. 2026-09-12 13:05 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  39. 2026-09-12 07:26 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  40. 2026-09-12 01:28 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  41. 2026-09-11 21:47 UTCEG score recompute
  42. 2026-09-11 21:47 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  43. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  44. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  45. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  46. 2026-09-08 00:58 UTCEG score recompute
  47. 2026-09-08 00:58 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  48. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  49. 2026-09-06 17:44 UTCEG score recompute
  50. 2026-09-06 17:44 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  51. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  52. 2026-09-06 13:29 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  53. 2026-09-06 04:35 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  54. 2026-09-06 00:33 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  55. 2026-09-05 20:52 UTCEG score recompute
  56. 2026-09-05 20:52 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  57. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  58. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  59. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  60. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  61. 2026-08-31 03:59 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  62. 2026-08-30 23:28 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  63. 2026-08-30 19:47 UTCEG score recompute
  64. 2026-08-30 19:47 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  65. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  66. 2026-08-30 16:06 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  67. 2026-08-30 11:18 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  68. 2026-08-30 07:37 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  69. 2026-08-30 03:56 UTCEG score recompute
  70. 2026-08-30 03:56 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  71. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  72. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  73. 2026-08-28 01:52 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3
  74. 2026-08-27 21:28 UTCEG score recompute
  75. 2026-08-27 21:28 UTCGHSA enrichmentGHSA-5p6h-xfw9-p64q · GitHub severity HIGH · GitHub CVSS 7.3

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-56398?
CVE-2026-56398 is a critical-severity vulnerability; its CVE record was published on July 15, 2026. Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs.…
When was CVE-2026-56398 made public?
CVE-2026-56398 was made public on May 10, 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-2026-56398 actively exploited?
CVE-2026-56398 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-56398?
CVE-2026-56398 has a CVSS v3 base score of 9.0 (NVD).
How do I remediate CVE-2026-56398?
A fix for CVE-2026-56398 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-56398 are linked in the Vendor Advisories panel on this page.

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