CVE-2026-93567

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-18. A secondary CVSS source baseline 7.5; 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-2026-82943 (ENISA EUVD) · GHSA-xf8w-rc87-x5gw (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2.6%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in Netty's HTTP/2 codec. When converting HTTP/1 CONNECT requests to HTTP/2, the component incorrectly uses the Host header instead of the CONNECT authority-form request-target for the tunnel authority. A remote attacker can exploit this by supplying a different Host header, leading to a malformed HTTP/2 CONNECT request. This can bypass security controls such as tunnel allow-lists or egress policies, resulting in integrity loss.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
50
EG Risk 50/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation2.6% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
2.6%
EPSS %ILE
85th
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
2.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days 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 low or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

September 18, 2026

Last Modified

October 19, 2026

Advisory Details (2)

Auto-updated Sep 18, 2026
Patch available. Sources: redhat.
Red Hat

2536955 – (CVE-2026-93567) CVE-2026-93567 io.netty/netty-codec-http2: HTTP/1 authority-form CONNECT is translated to malformed HTTP/2 CONNECT with Host-controlled :authority

https://bugzilla.redhat.com/show_bug.cgi?id=2536955
Red HatMentions a patch (unverified)

CVE-2026-93567 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-93567

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatnetty-codec-http22026-10-15redhat
redhatio.netty/netty-codec-http2:4.1.138.Final-redhat-000012026-09-22redhat

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

(3 across 3 ecosystems)
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
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 96× 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 169 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 69 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  4. 2026-10-29 16:34 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  5. 2026-10-28 16:33 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  6. 2026-10-27 17:51 UTCEG score recompute
  7. 2026-10-27 17:51 UTCVendor advisory
  8. 2026-10-27 17:51 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  9. 2026-10-27 16:33 UTCEPSS rescoreEPSS 2.6% · 85th percentile
  10. 2026-10-26 16:33 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  11. 2026-10-25 16:34 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  12. 2026-10-25 13:49 UTCEG score recompute
  13. 2026-10-24 16:34 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  14. 2026-10-23 16:33 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  17. 2026-10-20 16:34 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  19. 2026-10-19 11:27 UTCEG score recompute
  20. 2026-10-19 11:27 UTCVendor advisory
  21. 2026-10-19 11:27 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-10-19 10:49 UTCEG score recompute
  23. 2026-10-19 10:49 UTCVendor advisory
  24. 2026-10-19 10:49 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-10-18 16:33 UTCEPSS rescoreEPSS 2.6% · 84th percentile
Show 75 more
  1. 2026-10-18 15:35 UTCEG score recompute
  2. 2026-10-18 15:35 UTCVendor advisory
  3. 2026-10-18 15:35 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-10-18 02:58 UTCEG score recompute
  5. 2026-10-17 16:35 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  6. 2026-10-16 18:31 UTCEG score recompute
  7. 2026-10-16 18:31 UTCVendor advisory
  8. 2026-10-16 18:30 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  9. 2026-10-16 17:29 UTCEG score recompute
  10. 2026-10-16 17:29 UTCVendor advisory
  11. 2026-10-16 17:28 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  12. 2026-10-16 16:45 UTCEPSS rescoreEPSS 2.6% · 84th percentile
  13. 2026-10-15 17:28 UTCEG score recompute
  14. 2026-10-15 17:28 UTCVendor advisory
  15. 2026-10-15 17:27 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  16. 2026-10-15 16:50 UTCEG score recompute
  17. 2026-10-15 16:50 UTCVendor advisory
  18. 2026-10-15 16:49 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  19. 2026-10-15 16:33 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  20. 2026-10-14 16:34 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  21. 2026-10-13 16:35 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  22. 2026-10-13 04:25 UTCEG score recompute
  23. 2026-10-13 04:25 UTCVendor advisory
  24. 2026-10-13 04:25 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-10-12 16:35 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  26. 2026-10-12 14:43 UTCEG score recompute
  27. 2026-10-12 04:57 UTCVendor advisory
  28. 2026-10-12 04:57 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-10-11 19:12 UTCEG score recompute
  30. 2026-10-11 16:28 UTCEG score recompute
  31. 2026-10-11 15:34 UTCEG score recompute
  32. 2026-10-11 15:34 UTCVendor advisory
  33. 2026-10-11 15:34 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  34. 2026-10-11 13:50 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  35. 2026-10-11 13:41 UTCEG score recompute
  36. 2026-10-11 02:48 UTCEG score recompute
  37. 2026-10-11 02:48 UTCVendor advisory
  38. 2026-10-11 02:48 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  39. 2026-10-10 20:00 UTCEPSS rescoreEPSS 2.4% · 83rd percentile
  40. 2026-10-10 13:04 UTCVendor advisory
  41. 2026-10-10 13:04 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-10-10 00:18 UTCEG score recompute
  43. 2026-10-10 00:18 UTCVendor advisory
  44. 2026-10-10 00:17 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-10-09 23:20 UTCEG score recompute
  46. 2026-10-09 23:20 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-10-09 22:13 UTCEG score recompute
  48. 2026-10-09 22:12 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  49. 2026-10-09 20:08 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  50. 2026-10-09 09:26 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-10-08 20:40 UTCEG score recompute
  52. 2026-10-08 20:39 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  53. 2026-10-08 17:14 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  54. 2026-10-08 07:54 UTCEG score recompute
  55. 2026-10-08 07:53 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  56. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  57. 2026-10-07 19:06 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  58. 2026-10-07 06:19 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  59. 2026-10-06 17:32 UTCEG score recompute
  60. 2026-10-06 17:32 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  61. 2026-10-06 15:19 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  62. 2026-10-06 04:47 UTCEG score recompute
  63. 2026-10-06 04:47 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  64. 2026-10-05 17:44 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  65. 2026-10-05 16:00 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  66. 2026-10-05 02:43 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-10-04 13:57 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  68. 2026-10-04 01:11 UTCEG score recompute
  69. 2026-10-04 01:11 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  70. 2026-10-03 14:26 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  71. 2026-10-03 12:25 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  72. 2026-10-02 23:38 UTCEG score recompute
  73. 2026-10-02 23:38 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  74. 2026-10-02 10:49 UTCGHSA enrichmentGHSA-xf8w-rc87-x5gw · GitHub severity HIGH · GitHub CVSS 7.5
  75. 2026-10-01 21:53 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-93567?
CVE-2026-93567 is a high-severity vulnerability; its CVE record was published on September 18, 2026. A flaw was found in Netty's HTTP/2 codec. When converting HTTP/1 CONNECT requests to HTTP/2, the component incorrectly uses the Host header instead of the CONNECT authority-form request-target for the tunnel authority. A remote attacker can exploit this by supplying a different Host header, leading…
When was CVE-2026-93567 made public?
CVE-2026-93567 was made public on September 10, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on September 18, 2026. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-93567 actively exploited?
CVE-2026-93567 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.6% probability of exploitation in the next 30 days (85th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93567?
CVE-2026-93567 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-93567?
A fix for CVE-2026-93567 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-93567 are linked in the Vendor Advisories panel on this page.

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