CVE-2026-40110

HIGHNVD 7.37.3
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.3 under NVD CVSS v3. EPSS exploit probability: 0.5% (39th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this week
7.3EG
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: 0.5%CVSS: 7.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.

CVSS v3
7.3
EG Score
7.3HIGHmedium confidence
EG Risk
33
EG Risk 33/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity73% × 45%
Impact severity (EG Severity): CVSS 7.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (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.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.3): severity, escalated by confirmed exploitation. This CVE's 7.3 is its impact severity (EG Severity), not escalated.

EG Severity
7.3 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation none (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

May 5, 2026

Last Modified

July 24, 2026

Advisory Details (4)

Auto-updated May 5, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

CORS Origin Validation Bypass via `re.match()` in `allow_origin_pat` · Advisory · jupyter-server/jupyter_server · GitHub

https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p
Web page

Fix allow_origin_pat property to properly parse regex by havok2063 · Pull Request #603 · jupyter-server/jupyter_server · GitHub

https://github.com/jupyter-server/jupyter_server/pull/603
Web page

Move check origin into a util function and add it to websocket (#1630) · jupyter-server/jupyter_server@49b3439 · GitHub

https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8
Web page

Fix allow_origin_pat to do full matching instead of prefix matching · jupyter-server/jupyter_server@057869a · GitHub

https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea

Vendor Advisories for CVE-2026-40110(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17902609542026-09-30redhat
redhatmta/mta-solution-server-rhel9:17841098832026-07-21redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
jupyter-server1.10.2-1 ... 2.9.1-1 (28 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
jupyter-server1.23.3-1 ... 2.9.1-1 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
jupyter-server2.15.0-1, 2.17.0-1, 2.20.0-1, 2.20.0-2, 2.20.0-3
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
jupyter-server2.15.0-1, 2.17.0-1
  • every version up to 2.20.0-1: fixed in 2.20.0-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
jupyter-server0.0.0 ... 2.9.1 (155 versions)
  • every version up to 2.18.0: fixed in 2.18.0
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 32× 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 99 of 218 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 119 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  2. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  3. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-18 03:43 UTCEG score recompute
  6. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  7. 2026-10-17 14:55 UTCEG score recompute
  8. 2026-10-17 14:55 UTCVendor advisory
  9. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  12. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  14. 2026-10-12 16:09 UTCEG score recompute
  15. 2026-10-11 19:52 UTCEG score recompute
  16. 2026-10-11 17:05 UTCEG score recompute
  17. 2026-10-11 14:32 UTCEG score recompute
  18. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  19. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  21. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  22. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  24. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  25. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
Show 74 more
  1. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  2. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  4. 2026-09-30 10:11 UTCOSV refresh
  5. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  6. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  7. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  8. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  9. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  10. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  11. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  12. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  13. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  14. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  15. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  16. 2026-09-11 16:53 UTCOSV refresh
  17. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  18. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  19. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  20. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  21. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  22. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  23. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  24. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  25. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  26. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  27. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  28. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  29. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  30. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  31. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  32. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  33. 2026-08-23 20:31 UTCEG score recompute
  34. 2026-08-23 20:31 UTCVendor advisory
  35. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  36. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  37. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  38. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  39. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  40. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  41. 2026-08-17 13:00 UTCEG score recompute
  42. 2026-08-17 13:00 UTCVendor advisory
  43. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  44. 2026-08-16 04:57 UTCEG score recompute
  45. 2026-08-16 04:57 UTCVendor advisory
  46. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  47. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  48. 2026-08-14 15:09 UTCVendor advisory
  49. 2026-08-14 03:33 UTCEG score recompute
  50. 2026-08-14 03:33 UTCVendor advisory
  51. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  52. 2026-08-13 04:46 UTCVendor advisory
  53. 2026-08-12 17:11 UTCEG score recompute
  54. 2026-08-12 17:11 UTCVendor advisory
  55. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  56. 2026-08-11 16:02 UTCEG score recompute
  57. 2026-08-11 16:02 UTCVendor advisory
  58. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  59. 2026-08-11 01:35 UTCEG score recompute
  60. 2026-08-11 01:35 UTCVendor advisory
  61. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  62. 2026-08-10 13:40 UTCVendor advisory
  63. 2026-08-10 01:49 UTCVendor advisory
  64. 2026-08-09 14:14 UTCEG score recompute
  65. 2026-08-09 14:14 UTCVendor advisory
  66. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  67. 2026-08-09 02:38 UTCEG score recompute
  68. 2026-08-09 02:38 UTCVendor advisory
  69. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  70. 2026-08-08 10:26 UTCVendor advisory
  71. 2026-08-07 22:51 UTCEG score recompute
  72. 2026-08-07 22:51 UTCVendor advisory
  73. 2026-08-07 11:16 UTCVendor advisory
  74. 2026-08-06 21:46 UTCEG score recompute

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-40110?
CVE-2026-40110 is a high-severity vulnerability; its CVE record was published on May 5, 2026. Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the alloworiginpat configuration value. Because re.match() only anchors at the start of the string and does not require…
When was the CVE record for CVE-2026-40110 published?
The CVE record for CVE-2026-40110 was published on May 5, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 24, 2026; the record at its source may have been updated since.
Is CVE-2026-40110 actively exploited?
CVE-2026-40110 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40110?
CVE-2026-40110 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-40110?
A fix for CVE-2026-40110 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40110 are linked in the Vendor Advisories panel on this page.

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