CVE-2026-56746

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

Score 6.5 from GitHub Security Advisory (severity: MODERATE) published 2026-07-22. A secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-46998 (ENISA EUVD) · GHSA-6cqp-g7gg-8hr5 (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Netty is a network application framework for development of protocol servers and clients. Versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, are vulnerable to security control bypass during the origin evaluation process. CorsHandler provides a shortCircuit() configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an Origin: null header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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
0.4%
EPSS %ILE
35th
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 (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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.

The score's inputs: 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 21, 2026

Last Modified

July 30, 2026

Advisory Details (3)

Auto-updated Jul 22, 2026
Patch available. Sources: github_release, github.
GitHub advisoryMentions a patch (unverified)

Security Control Bypass via CORS Short-Circuit Failure · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-6cqp-g7gg-8hr5
GitHub release Patch Available

netty-4.2.16.Final

Patch available: netty/netty netty-4.2.16.Final

https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
GitHub release Patch Available

netty-4.1.136.Final

Patch available: netty/netty netty-4.1.136.Final

https://github.com/netty/netty/releases/tag/netty-4.1.136.Final

Patch Availability(13)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-modelmesh-rhel9:17908817002026-10-21redhat
redhatrhoai/odh-trustyai-service-rhel9:17917925252026-10-19redhat
redhatnetty-codec-http2026-10-06redhat
redhateap8-xml-security-0:3.0.6-1.redhat_00001.1.el9eap2026-09-22redhat
redhateap8-xml-security-0:3.0.6-1.redhat_00001.1.el8eap2026-09-22redhat
redhateap8-xml-security-0:3.0.6-1.redhat_00001.1.el10eap2026-09-22redhat
redhatio.netty/netty-codec-http:4.1.136.Final-redhat-000012026-09-22redhat
redhatdevspaces/server-rhel9:17891637982026-09-17redhat
redhatcryostat/jfr-datasource-rhel9:4.2.0-142026-09-16redhat
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
redhatdevspaces/pluginregistry-rhel9:17877597232026-09-01redhat
mavenio.netty:netty-codec-http @ 4.2.16.Final (fixes >= 4.2.0.Final, < 4.2.16.Final)—ghsa
mavenio.netty:netty-codec-http @ 4.1.136.Final (fixes < 4.1.136.Final)—ghsa

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
netty1:4.1.48-10 ... 1:4.1.48-9 (16 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)
  • every version on: no fix on record
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
io.netty:netty-codec-http4.0.0.Alpha1 ... 4.1.99.Final (229 versions)
  • 4.2.0.Final up to 4.2.16.Final: fixed in 4.2.16.Final
  • every version up to 4.1.136.Final: fixed in 4.1.136.Final
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 43× 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 216 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 116 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  2. 2026-11-01 07:42 UTCEG score recompute
  3. 2026-11-01 07:42 UTCGHSA enrichmentGHSA-6cqp-g7gg-8hr5 · GitHub severity MODERATE · GitHub CVSS 6.5
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-10-30 10:25 UTCOSV refresh
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  12. 2026-10-25 14:18 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  15. 2026-10-22 21:08 UTCEG score recompute
  16. 2026-10-22 21:08 UTCVendor advisory
  17. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  18. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  20. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-10-18 03:29 UTCEG score recompute
  23. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  24. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
Show 75 more
  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  4. 2026-10-12 15:54 UTCEG score recompute
  5. 2026-10-11 19:38 UTCEG score recompute
  6. 2026-10-11 16:53 UTCEG score recompute
  7. 2026-10-11 14:16 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  13. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  14. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  15. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  16. 2026-10-04 13:44 UTCEG score recompute
  17. 2026-10-04 13:44 UTCVendor advisory
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  21. 2026-10-01 07:00 UTCEG score recompute
  22. 2026-10-01 07:00 UTCVendor advisory
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  24. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  26. 2026-09-28 05:44 UTCEG score recompute
  27. 2026-09-28 05:44 UTCVendor advisory
  28. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  29. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  30. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  31. 2026-09-23 22:37 UTCEG score recompute
  32. 2026-09-23 22:37 UTCVendor advisory
  33. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  34. 2026-09-23 00:40 UTCEG score recompute
  35. 2026-09-23 00:40 UTCVendor advisory
  36. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  37. 2026-09-20 04:11 UTCEG score recompute
  38. 2026-09-20 04:11 UTCVendor advisory
  39. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  40. 2026-09-18 08:03 UTCEG score recompute
  41. 2026-09-18 08:03 UTCVendor advisory
  42. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  43. 2026-09-17 10:10 UTCEG score recompute
  44. 2026-09-17 10:10 UTCVendor advisory
  45. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  46. 2026-09-16 12:18 UTCEG score recompute
  47. 2026-09-16 12:18 UTCVendor advisory
  48. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  49. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  50. 2026-09-13 23:34 UTCEG score recompute
  51. 2026-09-13 23:34 UTCVendor advisory
  52. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  53. 2026-09-13 01:42 UTCEG score recompute
  54. 2026-09-13 01:42 UTCVendor advisory
  55. 2026-09-12 01:27 UTCEG score recompute
  56. 2026-09-12 01:27 UTCVendor advisory
  57. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  58. 2026-09-11 03:35 UTCEG score recompute
  59. 2026-09-11 03:35 UTCVendor advisory
  60. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  61. 2026-09-09 09:53 UTCEG score recompute
  62. 2026-09-09 09:53 UTCVendor advisory
  63. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  64. 2026-09-07 21:58 UTCEG score recompute
  65. 2026-09-07 21:58 UTCVendor advisory
  66. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  67. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  68. 2026-09-06 05:49 UTCEG score recompute
  69. 2026-09-06 05:49 UTCVendor advisory
  70. 2026-09-05 07:44 UTCEG score recompute
  71. 2026-09-05 07:44 UTCVendor advisory
  72. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  73. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  74. 2026-09-01 23:54 UTCEG score recompute
  75. 2026-09-01 23:54 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-56746?
CVE-2026-56746 is a medium-severity vulnerability; its CVE record was published on July 21, 2026. Netty is a network application framework for development of protocol servers and clients. Versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, are vulnerable to security control bypass during the origin evaluation process. CorsHandler provides a shortCircuit()…
When was the CVE record for CVE-2026-56746 published?
The CVE record for CVE-2026-56746 was published on July 21, 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 30, 2026; the record at its source may have been updated since.
Is CVE-2026-56746 actively exploited?
CVE-2026-56746 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-56746?
CVE-2026-56746 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-56746?
A fix for CVE-2026-56746 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-56746 are linked in the Vendor Advisories panel on this page.

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