CVE-2026-44248

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 60% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

May 13, 2026

Last Modified

August 3, 2026

Advisory Details (1)

Auto-updated May 18, 2026
Patch available. Sources: github.
github Patch Available

MQTT: Resource exhaustion in MqttDecoder · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx

Vendor Advisories for CVE-2026-44248(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnetty-codec-mqtt2026-07-20redhat

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 rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (16 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)——
Maven(1)
PackageVulnerable rangeFixed inDependents
io.netty:netty-codec-mqtt4.1.0.Beta1 ... 4.1.99.Final (148 versions)4.1.133.Final—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 55× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 174 total refreshes for this CVE.

  1. 2026-09-06 13:47 UTCEPSS rescore
  2. 2026-09-04 05:06 UTCEPSS rescore
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 13:54 UTCEPSS rescore
  5. 2026-08-30 19:17 UTCEPSS rescore
  6. 2026-08-30 01:22 UTCEPSS rescore
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-26 14:46 UTCEPSS rescore
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-23 17:50 UTCEG score recompute
  12. 2026-08-23 17:50 UTCVendor advisory
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 02:05 UTCEG score recompute
  15. 2026-08-22 02:05 UTCVendor advisory
  16. 2026-08-21 23:49 UTCEPSS rescore
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-20 19:47 UTCEG score recompute
  19. 2026-08-20 19:47 UTCVendor advisory
  20. 2026-08-19 17:04 UTCEPSS rescore
  21. 2026-08-18 13:48 UTCEPSS rescore
  22. 2026-08-17 13:47 UTCEPSS rescore
  23. 2026-08-17 10:30 UTCEG score recompute
  24. 2026-08-17 10:30 UTCVendor advisory
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 75 more
  1. 2026-08-16 04:02 UTCEG score recompute
  2. 2026-08-16 04:02 UTCVendor advisory
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-15 00:53 UTCVendor advisory
  6. 2026-08-14 13:41 UTCVendor advisory
  7. 2026-08-14 02:30 UTCEG score recompute
  8. 2026-08-14 02:30 UTCVendor advisory
  9. 2026-08-13 22:00 UTCEPSS rescore
  10. 2026-08-13 03:00 UTCVendor advisory
  11. 2026-08-12 15:49 UTCEG score recompute
  12. 2026-08-12 15:49 UTCVendor advisory
  13. 2026-08-12 13:51 UTCEPSS rescore
  14. 2026-08-11 15:27 UTCEG score recompute
  15. 2026-08-11 15:27 UTCVendor advisory
  16. 2026-08-11 13:43 UTCEPSS rescore
  17. 2026-08-11 00:56 UTCEG score recompute
  18. 2026-08-11 00:56 UTCVendor advisory
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 11:30 UTCVendor advisory
  21. 2026-08-10 00:17 UTCEG score recompute
  22. 2026-08-10 00:17 UTCVendor advisory
  23. 2026-08-09 13:46 UTCEPSS rescore
  24. 2026-08-09 13:05 UTCVendor advisory
  25. 2026-08-09 01:54 UTCEG score recompute
  26. 2026-08-09 01:54 UTCVendor advisory
  27. 2026-08-08 16:37 UTCEPSS rescore
  28. 2026-08-08 06:01 UTCVendor advisory
  29. 2026-08-07 18:49 UTCEG score recompute
  30. 2026-08-07 18:49 UTCVendor advisory
  31. 2026-08-07 07:22 UTCVendor advisory
  32. 2026-08-06 20:03 UTCEG score recompute
  33. 2026-08-06 20:03 UTCVendor advisory
  34. 2026-08-06 13:46 UTCEPSS rescore
  35. 2026-08-06 08:52 UTCVendor advisory
  36. 2026-08-05 21:40 UTCEG score recompute
  37. 2026-08-05 21:40 UTCVendor advisory
  38. 2026-08-05 19:17 UTCEPSS rescore
  39. 2026-08-04 15:10 UTCEPSS rescore
  40. 2026-08-04 10:38 UTCEPSS rescore
  41. 2026-08-04 00:55 UTCVendor advisory
  42. 2026-08-03 13:43 UTCVendor advisory
  43. 2026-08-03 12:47 UTCEG score recompute
  44. 2026-08-03 12:47 UTCVendor advisory
  45. 2026-08-03 10:36 UTCEPSS rescore
  46. 2026-08-02 19:19 UTCVendor advisory
  47. 2026-08-02 08:07 UTCEG score recompute
  48. 2026-08-02 08:07 UTCVendor advisory
  49. 2026-08-02 02:27 UTCEPSS rescore
  50. 2026-08-01 19:44 UTCEG score recompute
  51. 2026-08-01 19:44 UTCVendor advisory
  52. 2026-08-01 04:16 UTCEPSS rescore
  53. 2026-07-30 16:28 UTCEPSS rescore
  54. 2026-07-30 12:25 UTCVendor advisory
  55. 2026-07-30 12:07 UTCEG score recompute
  56. 2026-07-30 12:07 UTCVendor advisory
  57. 2026-07-30 01:30 UTCEPSS rescore
  58. 2026-07-28 15:36 UTCEPSS rescore
  59. 2026-07-27 14:13 UTCEPSS rescore
  60. 2026-07-26 14:54 UTCEPSS rescore
  61. 2026-07-26 14:54 UTCEPSS rescore
  62. 2026-07-25 14:18 UTCEPSS rescore
  63. 2026-07-24 14:17 UTCEPSS rescore
  64. 2026-07-23 14:18 UTCEPSS rescore
  65. 2026-07-23 03:14 UTCEG score recompute▲ 2.20
  66. 2026-07-22 14:08 UTCEPSS rescore
  67. 2026-07-21 15:24 UTCEPSS rescore
  68. 2026-07-20 17:08 UTCEPSS rescore
  69. 2026-07-19 14:31 UTCEPSS rescore
  70. 2026-07-19 02:29 UTCEPSS rescore
  71. 2026-07-18 10:04 UTCEPSS rescore
  72. 2026-07-18 02:29 UTCOSV refresh
  73. 2026-07-16 17:03 UTCEPSS rescore
  74. 2026-07-15 16:57 UTCEPSS rescore
  75. 2026-07-15 02:25 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH

Frequently asked(5)

What is CVE-2026-44248?
CVE-2026-44248 is a high vulnerability 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, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the…
When was CVE-2026-44248 disclosed?
CVE-2026-44248 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on August 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44248 actively exploited?
CVE-2026-44248 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 59.7% of all scored CVEs.
What is the CVSS score of CVE-2026-44248?
CVE-2026-44248 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-44248?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44248, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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