CVE-2026-93491

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

Also known asEUVD-2026-82902 (ENISA EUVD) · GHSA-c593-fgx2-8jj6 (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: 0.9%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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.
Exploitation0.7% × 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
0.9%
EPSS %ILE
59th
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
0.9% within 30 daysSource: FIRST EPSS. 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

November 6, 2026

Advisory Details (4)

Auto-updated Sep 18, 2026
Patch available. Sources: github_release, redhat.
GitHub release Patch Available

netty-4.2.18.Final

Patch available: netty/netty netty-4.2.18.Final

https://github.com/netty/netty/releases/tag/netty-4.2.18.Final
GitHub release Patch Available

netty-4.1.138.Final

Patch available: netty/netty netty-4.1.138.Final

https://github.com/netty/netty/releases/tag/netty-4.1.138.Final
Red Hat

2536891 – (CVE-2026-93491) CVE-2026-93491 io.netty/netty-codec-http: Netty: Denial of Service via unbounded HttpServerCodec HTTP/1.1 pipeline queue

https://bugzilla.redhat.com/show_bug.cgi?id=2536891
Red HatMentions a patch (unverified)

CVE-2026-93491 - 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-2026-93491

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatkeycloak-rhel9-operator-container-26.4-302026-11-06redhat
redhatnetty-codec-http2026-11-06redhat
redhatio.netty/netty-codec-http: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 7× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 184 rows 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 84 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:58 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  2. 2026-11-12 16:35 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  3. 2026-11-11 16:41 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  4. 2026-11-10 16:46 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  5. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  6. 2026-11-08 16:41 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  7. 2026-11-07 16:40 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  8. 2026-11-06 17:28 UTCEchelonGraph re-scored
  9. 2026-11-06 17:28 UTCVendor advisory
  10. 2026-11-06 17:28 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  11. 2026-11-06 17:18 UTCEchelonGraph re-scored
  12. 2026-11-06 17:18 UTCVendor advisory
  13. 2026-11-06 17:18 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-11-06 16:40 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  15. 2026-11-06 16:28 UTCEchelonGraph re-scored
  16. 2026-11-06 16:28 UTCVendor advisory
  17. 2026-11-06 16:28 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  18. 2026-11-06 11:27 UTCEchelonGraph re-scored
  19. 2026-11-06 11:27 UTCVendor advisory
  20. 2026-11-06 11:27 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  21. 2026-11-06 10:28 UTCEchelonGraph re-scored
  22. 2026-11-06 10:28 UTCVendor advisory
  23. 2026-11-06 10:28 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  24. 2026-11-05 16:39 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  25. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.7% · 54th percentile
Show 75 more
  1. 2026-11-03 17:19 UTCEchelonGraph re-scored
  2. 2026-11-03 17:19 UTCVendor advisory
  3. 2026-11-03 17:19 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  5. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  6. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  7. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  8. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  9. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  10. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  11. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  12. 2026-10-27 12:11 UTCEchelonGraph re-scored
  13. 2026-10-27 12:11 UTCVendor advisory
  14. 2026-10-27 12:11 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  15. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  16. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  17. 2026-10-25 13:49 UTCEchelonGraph re-scored
  18. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  19. 2026-10-23 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  20. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  21. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  22. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  23. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  24. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  25. 2026-10-18 15:35 UTCEchelonGraph re-scored
  26. 2026-10-18 15:35 UTCVendor advisory
  27. 2026-10-18 15:35 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  28. 2026-10-18 02:59 UTCEchelonGraph re-scored
  29. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  30. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  31. 2026-10-15 17:28 UTCEchelonGraph re-scored
  32. 2026-10-15 17:28 UTCVendor advisory
  33. 2026-10-15 17:28 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  34. 2026-10-15 16:50 UTCEchelonGraph re-scored
  35. 2026-10-15 16:50 UTCVendor advisory
  36. 2026-10-15 16:49 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  37. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  38. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  39. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  40. 2026-10-13 04:26 UTCEchelonGraph re-scored
  41. 2026-10-13 04:26 UTCVendor advisory
  42. 2026-10-13 04:26 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  43. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  44. 2026-10-12 14:43 UTCEchelonGraph re-scored
  45. 2026-10-12 04:57 UTCVendor advisory
  46. 2026-10-12 04:57 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-10-11 19:12 UTCEchelonGraph re-scored
  48. 2026-10-11 16:28 UTCEchelonGraph re-scored
  49. 2026-10-11 15:24 UTCEchelonGraph re-scored
  50. 2026-10-11 15:24 UTCVendor advisory
  51. 2026-10-11 15:24 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  52. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  53. 2026-10-11 13:42 UTCEchelonGraph re-scored
  54. 2026-10-11 02:48 UTCEchelonGraph re-scored
  55. 2026-10-11 02:48 UTCVendor advisory
  56. 2026-10-11 02:48 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  57. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  58. 2026-10-10 12:53 UTCVendor advisory
  59. 2026-10-10 12:53 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  60. 2026-10-10 00:18 UTCEchelonGraph re-scored
  61. 2026-10-10 00:18 UTCVendor advisory
  62. 2026-10-10 00:18 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  63. 2026-10-09 23:20 UTCEchelonGraph re-scored
  64. 2026-10-09 23:20 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  66. 2026-10-09 18:44 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-10-09 06:07 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  68. 2026-10-08 17:31 UTCEchelonGraph re-scored
  69. 2026-10-08 17:31 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  70. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  71. 2026-10-08 02:13 UTCEchelonGraph re-scored
  72. 2026-10-08 02:13 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  73. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  74. 2026-10-07 13:37 UTCGHSA enrichmentGHSA-c593-fgx2-8jj6 · GitHub severity HIGH · GitHub CVSS 7.5
  75. 2026-10-07 00:57 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-93491?
CVE-2026-93491 is a high-severity vulnerability; its CVE record was published on September 18, 2026. A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption…
When was CVE-2026-93491 made public?
CVE-2026-93491 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 November 6, 2026; the record at its source may have been updated since.
Is CVE-2026-93491 actively exploited?
CVE-2026-93491 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (59th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93491?
CVE-2026-93491 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-2026-93491?
A fix for CVE-2026-93491 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-93491 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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