CVE-2026-42584

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.8% (58th 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 2026-05-07) is not newer than that change (2026-10-26), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Elevated

Also known asEUVD-2026-30127 (ENISA EUVD) · GHSA-57rv-r2g8-2cj3 (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.8%CVSS: 9.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
72
EG Risk 72/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (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
0.8%
EPSS %ILE
58th
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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 public PoC (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

May 13, 2026

Last Modified

October 26, 2026

Advisory Details (13)

Auto-updated Sep 15, 2026
Patch available. Sources: github, redhat.
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 7. Red Hat Product Security has rated

https://access.redhat.com/errata/RHSA-2026:53644
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:49700
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:42644
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:37390
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:36820
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:28010
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:25123
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:24502
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:23808
GitHub advisoryMentions a patch (unverified)

HttpClientCodec response desynchronization · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-57rv-r2g8-2cj3
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:53806
Red HatMentions a patch (unverified)

2477224 – (CVE-2026-42584) CVE-2026-42584 netty: io.netty/netty-codec-http: Netty: Incorrect HTTP response parsing leads to data confusion

https://bugzilla.redhat.com/show_bug.cgi?id=2477224
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-42584

Patch Availability(19)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibnetty-java (1:4.1.45-1ubuntu0.1~esm6) @ focal2026-11-12ubuntu
redhatrhoai/odh-trustyai-service-rhel9:17917925252026-10-19redhat
redhateap7-wildfly-0:7.1.16-1.GA_redhat_00002.1.ep7.el72026-09-30redhat
redhateap7-wildfly-0:7.3.19-1.GA_redhat_00004.1.el7eap2026-09-30redhat
redhatnetty-codec-http2026-09-21redhat
redhatrhoai/odh-trustyai-service-rhel9:17881986812026-09-08redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el9eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el8eap2026-08-11redhat
redhateap8-wildfly-0:8.1.7.1-1.GA_redhat_00004.1.el9eap2026-08-03redhat
redhatio.netty/netty-codec-http:4.1.135.Final-redhat-000012026-08-03redhat
redhatrhoai/odh-modelmesh-rhel9:17834438162026-07-21redhat
redhatdevspaces/multicluster-redirector-rhel9:17829890272026-07-08redhat
redhatpatch2026-06-25redhat
redhatcryostat/jfr-datasource-rhel9:4.2.0-102026-06-22redhat
redhatdevspaces/server-rhel9:17806949942026-06-10redhat
redhatio.netty/netty-codec-http:4.1.133.Final-redhat-000022026-06-10redhat
mavenio.netty:netty-codec-http @ 4.2.13.Final (fixes >= 4.2.0.Alpha1, <= 4.2.12.Final)—ghsa
mavenio.netty:netty-codec-http @ 4.1.133.Final (fixes <= 4.1.132.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 (226 versions)
  • 4.2.0.Alpha1 up to 4.2.13.Final: fixed in 4.2.13.Final
  • every version up to 4.1.133.Final: fixed in 4.1.133.Final
—

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 23× in last 7d / 76× 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 403 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 303 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 09:15 UTCEchelonGraph re-scored
  2. 2026-11-13 09:15 UTCVendor advisory
  3. 2026-11-13 09:15 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  4. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  5. 2026-11-12 10:59 UTCEchelonGraph re-scored
  6. 2026-11-12 10:59 UTCVendor advisory
  7. 2026-11-12 10:59 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  8. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  9. 2026-11-11 12:41 UTCEchelonGraph re-scored
  10. 2026-11-11 12:41 UTCVendor advisory
  11. 2026-11-11 12:41 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  12. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  13. 2026-11-10 14:24 UTCEchelonGraph re-scored
  14. 2026-11-10 14:24 UTCVendor advisory
  15. 2026-11-10 14:24 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  16. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  17. 2026-11-09 16:08 UTCVendor advisory
  18. 2026-11-09 16:08 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  19. 2026-11-08 17:48 UTCEchelonGraph re-scored
  20. 2026-11-08 17:48 UTCVendor advisory
  21. 2026-11-08 17:48 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  22. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  23. 2026-11-07 19:31 UTCEchelonGraph re-scored
  24. 2026-11-07 19:31 UTCVendor advisory
  25. 2026-11-07 19:31 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
Show 75 more
  1. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.8% · 58th percentile
  2. 2026-11-06 21:14 UTCEchelonGraph re-scored
  3. 2026-11-06 21:14 UTCVendor advisory
  4. 2026-11-06 21:14 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  5. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  6. 2026-11-06 08:25 UTCOSV refresh
  7. 2026-11-05 22:57 UTCEchelonGraph re-scored
  8. 2026-11-05 22:57 UTCVendor advisory
  9. 2026-11-05 22:57 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  10. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  11. 2026-11-05 00:41 UTCEchelonGraph re-scored
  12. 2026-11-05 00:41 UTCVendor advisory
  13. 2026-11-05 00:41 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  14. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  15. 2026-11-04 02:24 UTCEchelonGraph re-scored
  16. 2026-11-04 02:24 UTCVendor advisory
  17. 2026-11-04 02:24 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  18. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  19. 2026-11-03 04:08 UTCEchelonGraph re-scored
  20. 2026-11-03 04:08 UTCVendor advisory
  21. 2026-11-03 04:08 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  22. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  23. 2026-11-02 05:46 UTCEchelonGraph re-scored
  24. 2026-11-02 05:46 UTCVendor advisory
  25. 2026-11-02 05:46 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  26. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  27. 2026-11-01 07:50 UTCGHSA enrichmentGHSA-57rv-r2g8-2cj3 · GitHub severity HIGH · GitHub CVSS 7.3
  28. 2026-11-01 07:50 UTCEchelonGraph re-scored
  29. 2026-11-01 07:30 UTCEchelonGraph re-scored
  30. 2026-11-01 07:30 UTCVendor advisory
  31. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  32. 2026-10-31 09:13 UTCEchelonGraph re-scored
  33. 2026-10-31 09:13 UTCVendor advisory
  34. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  35. 2026-10-30 10:57 UTCEchelonGraph re-scored
  36. 2026-10-30 10:57 UTCVendor advisory
  37. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  38. 2026-10-29 12:42 UTCEchelonGraph re-scored
  39. 2026-10-29 12:42 UTCVendor advisory
  40. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  41. 2026-10-28 14:25 UTCEchelonGraph re-scored
  42. 2026-10-28 14:25 UTCVendor advisory
  43. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  44. 2026-10-27 15:49 UTCVendor advisory
  45. 2026-10-26 17:29 UTCEchelonGraph re-scored
  46. 2026-10-26 17:29 UTCVendor advisory
  47. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  48. 2026-10-25 20:30 UTCEchelonGraph re-scored
  49. 2026-10-25 20:30 UTCVendor advisory
  50. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  51. 2026-10-25 14:29 UTCEchelonGraph re-scored
  52. 2026-10-24 22:14 UTCEchelonGraph re-scored
  53. 2026-10-24 22:14 UTCVendor advisory
  54. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  55. 2026-10-23 23:53 UTCEchelonGraph re-scored
  56. 2026-10-23 23:53 UTCVendor advisory
  57. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  58. 2026-10-23 01:31 UTCEchelonGraph re-scored
  59. 2026-10-23 01:31 UTCVendor advisory
  60. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  61. 2026-10-22 02:51 UTCEchelonGraph re-scored
  62. 2026-10-22 02:51 UTCVendor advisory
  63. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  64. 2026-10-21 04:28 UTCEchelonGraph re-scored
  65. 2026-10-21 04:28 UTCVendor advisory
  66. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  67. 2026-10-20 06:10 UTCEchelonGraph re-scored
  68. 2026-10-20 06:10 UTCVendor advisory
  69. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  70. 2026-10-19 07:51 UTCEchelonGraph re-scored
  71. 2026-10-19 07:51 UTCVendor advisory
  72. 2026-10-18 09:32 UTCVendor advisory
  73. 2026-10-18 03:40 UTCEchelonGraph re-scored
  74. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  75. 2026-10-17 11:15 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-42584?
CVE-2026-42584 is a critical-severity vulnerability; its CVE record was published on May 13, 2026. Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103,…
When was the CVE record for CVE-2026-42584 published?
The CVE record for CVE-2026-42584 was published on May 13, 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 October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-42584 actively exploited?
CVE-2026-42584 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (58th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42584?
CVE-2026-42584 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-42584?
A fix for CVE-2026-42584 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42584 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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