CVE-2026-89044

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 published 2026-09-10. 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

Also known asEUVD-2026-75633 (ENISA EUVD) · GHSA-77qf-r755-9gcw (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the final transfer coding in the Transfer-Encoding header, allowing attackers to smuggle requests by using malformed encoding declarations. Attackers can split Transfer-Encoding headers across multiple lines or use values like 'chunked, xchunked' to bypass validation and decode messages as chunked when the final coding is not chunked, enabling request smuggling attacks.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
44
EG Risk 44/100

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.
Exploitation0.3% × 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
0.3%
EPSS %ILE
20th
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
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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 10, 2026

Last Modified

September 18, 2026

Advisory Details (8)

Auto-updated Sep 10, 2026
Patch available. Sources: github, github_commit, github_release.
Web page

Netty 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final HTTP Request Smuggling via Transfer-Encoding | Advisories | VulnCheck

https://www.vulncheck.com/advisories/netty-4.1.133-final-through-4.1.137-final-and-4.2.13-final-through-4.2.17-final-http-request-smuggling-via-transfer-encoding
Web page

GitHub - netty/netty: Netty project - an event-driven asynchronous network application framework · GitHub

https://github.com/netty/netty
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
Web page

netty/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java at netty-4.1.137.Final · netty/netty · GitHub

https://github.com/netty/netty/blob/netty-4.1.137.Final/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java#L866
GitHub commit Patch Available

commit 640d4d3324f7 (netty/netty)

Patch available: netty/netty netty-4.2.18.Final (contains commit 640d4d3324f7)

https://github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500c
GitHub commit Patch Available

commit ca87393b0e9e (netty/netty)

Patch available: netty/netty netty-4.1.138.Final (contains commit ca87393b0e9e)

https://github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585
GitHub advisoryMentions a patch (unverified)

Incomplete validation of malformed Transfer-Encoding allows HTTP request smuggling · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5c

Vendor Advisories for CVE-2026-89044(1)

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

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 8× in last 7d / 53× 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 119 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 19 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 0.3% · 20th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  4. 2026-10-29 22:25 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  10. 2026-10-25 13:53 UTCEG score recompute
  11. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-22 12:32 UTCEG score recompute
  15. 2026-10-22 12:32 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  19. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  20. 2026-10-18 03:03 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  22. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  23. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  24. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  25. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
Show 75 more
  1. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  2. 2026-10-12 14:49 UTCEG score recompute
  3. 2026-10-11 19:15 UTCEG score recompute
  4. 2026-10-11 16:32 UTCEG score recompute
  5. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  6. 2026-10-11 13:48 UTCEG score recompute
  7. 2026-10-11 10:18 UTCEG score recompute
  8. 2026-10-11 10:18 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  10. 2026-10-10 08:26 UTCEG score recompute
  11. 2026-10-10 08:26 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  13. 2026-10-09 06:32 UTCEG score recompute
  14. 2026-10-09 06:32 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  15. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  16. 2026-10-08 04:35 UTCEG score recompute
  17. 2026-10-08 04:35 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  19. 2026-10-07 02:43 UTCEG score recompute
  20. 2026-10-07 02:43 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  21. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  22. 2026-10-06 00:52 UTCEG score recompute
  23. 2026-10-06 00:52 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  24. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  25. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  26. 2026-10-04 22:59 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  27. 2026-10-03 21:08 UTCEG score recompute
  28. 2026-10-03 21:08 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  29. 2026-10-02 19:16 UTCEG score recompute
  30. 2026-10-02 19:16 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  31. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  32. 2026-10-01 17:22 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  33. 2026-09-30 15:22 UTCEG score recompute
  34. 2026-09-30 15:22 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  35. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  36. 2026-09-29 13:30 UTCEG score recompute
  37. 2026-09-29 13:30 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  38. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  39. 2026-09-28 11:18 UTCEG score recompute
  40. 2026-09-28 11:18 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  41. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  42. 2026-09-27 09:26 UTCEG score recompute
  43. 2026-09-27 09:26 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  44. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  45. 2026-09-26 07:35 UTCEG score recompute
  46. 2026-09-26 07:35 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  47. 2026-09-25 05:44 UTCEG score recompute
  48. 2026-09-25 05:44 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  49. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  50. 2026-09-24 03:53 UTCEG score recompute
  51. 2026-09-24 03:53 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  52. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  53. 2026-09-23 02:00 UTCEG score recompute
  54. 2026-09-23 02:00 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  55. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  56. 2026-09-22 00:08 UTCEG score recompute
  57. 2026-09-22 00:08 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  58. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  59. 2026-09-20 22:16 UTCEG score recompute
  60. 2026-09-20 22:16 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  61. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  62. 2026-09-19 20:24 UTCEG score recompute
  63. 2026-09-19 20:24 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  64. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  65. 2026-09-18 18:33 UTCEG score recompute
  66. 2026-09-18 18:33 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  67. 2026-09-18 17:29 UTCEG score recompute
  68. 2026-09-18 17:29 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  69. 2026-09-17 19:46 UTCEG score recompute
  70. 2026-09-17 19:46 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  71. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  72. 2026-09-16 16:06 UTCEG score recompute
  73. 2026-09-16 16:06 UTCGHSA enrichmentGHSA-77qf-r755-9gcw · GitHub CVSS 6.5
  74. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  75. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 16th percentile

Frequently asked(5)

What is CVE-2026-89044?
CVE-2026-89044 is a medium-severity vulnerability; its CVE record was published on September 10, 2026. Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the final transfer coding in the Transfer-Encoding header, allowing attackers to smuggle requests by using malformed encoding declarations. Attackers can split Transfer-Encoding…
When was CVE-2026-89044 made public?
CVE-2026-89044 was made public on July 20, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 10, 2026. EchelonGraph's copy of the record carries a last-modified date of September 18, 2026; the record at its source may have been updated since.
Is CVE-2026-89044 actively exploited?
CVE-2026-89044 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (20th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89044?
CVE-2026-89044 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-2026-89044?
A fix for CVE-2026-89044 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-89044 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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