Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded maxHeaderSize and marked the frame truncated in SpdyFrameCodec, allowing a remote peer to send a small compressed HEADERS block that expands into much larger raw header data and causes compression-amplified CPU and allocation churn. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
CVE-2026-55833
“—” beside the score: it is equal to the CVSS score beside it.
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7% (51st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-46133 (ENISA EUVD) · GHSA-mvh2-crg5-v77c (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 49EG 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
- 0.7%
- EPSS %ILE
- 51st
- 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.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.7% 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: 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.
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
July 20, 2026
Last Modified
July 23, 2026
Advisory Details (5)
Auto-updated Jul 21, 2026Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation · Advisory · netty/netty · GitHub
https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77cnetty-4.2.16.Final
Patch available: netty/netty netty-4.2.16.Final
https://github.com/netty/netty/releases/tag/netty-4.2.16.Finalnetty-4.1.136.Final
Patch available: netty/netty netty-4.1.136.Final
https://github.com/netty/netty/releases/tag/netty-4.1.136.Finalcommit bb2ff68a1fb7 (netty/netty)
Patch available: netty/netty netty-4.1.136.Final (contains commit bb2ff68a1fb7)
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6commit 5b68c61f37aa (netty/netty)
Patch available: netty/netty netty-4.2.16.Final (contains commit 5b68c61f37aa)
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bVendor Advisories for CVE-2026-55833(19)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:87410Red Hat Product SecurityCritical
Red Hat Security Advisory: RHOAI 2.25.12 - Red Hat OpenShift AI
- RHSA-2026:84734Red Hat Product SecurityCritical
Red Hat Security Advisory: RHOAI 3.4.5 - Red Hat OpenShift AI
- RHSA-2026:76637Red Hat Product SecurityHigh
Red Hat Security Advisory: Apicurio Registry (container images) release and security update [ 3.3.3 GA ]
- RHSA-2026:70277Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
- RHSA-2026:70230Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
- RHSA-2026:70228Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
- RHSA-2026:70229Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
- RHSA-2026:69296Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Data Grid 8.6.3 security update
- +11 more
Patch Availability(13)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | rhoai/odh-modelmesh-rhel9:1790881700 | 2026-10-21 | redhat |
| redhat | rhoai/odh-trustyai-service-rhel9:1791792525 | 2026-10-19 | redhat |
| redhat | netty-codec-http | 2026-10-06 | redhat |
| redhat | eap8-xml-security-0:3.0.6-1.redhat_00001.1.el8eap | 2026-09-22 | redhat |
| redhat | eap8-xml-security-0:3.0.6-1.redhat_00001.1.el10eap | 2026-09-22 | redhat |
| redhat | eap8-xml-security-0:3.0.6-1.redhat_00001.1.el9eap | 2026-09-22 | redhat |
| redhat | io.netty/netty-codec-http:4.1.136.Final-redhat-00001 | 2026-09-22 | redhat |
| redhat | devspaces/server-rhel9:1789163798 | 2026-09-17 | redhat |
| redhat | cryostat/jfr-datasource-rhel9:4.2.0-14 | 2026-09-16 | redhat |
| redhat | rhoai/odh-trustyai-service-rhel9:1788198681 | 2026-09-08 | redhat |
| redhat | devspaces/pluginregistry-rhel9:1787759723 | 2026-09-01 | redhat |
| redhat | patch | 2026-08-05 | redhat |
| redhat | patch | 2026-08-05 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| netty | 1:4.1.48-10 ... 1:4.1.48-9 (16 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| netty | 1:4.1.48-10 ... 1:4.1.48-9 (12 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| netty | 1:4.1.48-10 ... 1:4.1.48-16 (8 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| netty | 1:4.1.48-10 ... 1:4.1.48-16 (7 versions) |
| — |
Maven(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| io.netty:netty-codec-http | 4.1.0.Final ... 4.1.99.Final (136 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(2)
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 10× in last 7d / 46× 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 235 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 135 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-25 14:18 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-23 14:21 UTCEG score recompute
- 2026-10-23 14:21 UTCVendor advisory
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-18 03:29 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-17 03:12 UTCEG score recompute
- 2026-10-17 03:12 UTCVendor advisory
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-12 15:55 UTCEG score recompute
- 2026-10-11 19:38 UTCEG score recompute
- 2026-10-11 16:53 UTCEG score recompute
- 2026-10-11 14:16 UTCEG score recompute
Show 75 moreShow fewer
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-04 14:53 UTCEG score recompute
- 2026-10-04 14:53 UTCVendor advisory
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 50th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-10-01 07:38 UTCEG score recompute
- 2026-10-01 07:38 UTCVendor advisory
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-28 06:17 UTCEG score recompute
- 2026-09-28 06:17 UTCVendor advisory
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-24 03:26 UTCEG score recompute
- 2026-09-24 03:26 UTCVendor advisory
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-23 01:35 UTCEG score recompute
- 2026-09-23 01:35 UTCVendor advisory
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-20 06:09 UTCEG score recompute
- 2026-09-20 06:09 UTCVendor advisory
- 2026-09-19 00:29 UTCEG score recompute
- 2026-09-19 00:29 UTCVendor advisory
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-18 03:54 UTCEG score recompute
- 2026-09-18 03:54 UTCVendor advisory
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-17 05:08 UTCEG score recompute
- 2026-09-17 05:08 UTCVendor advisory
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-16 12:45 UTCEG score recompute
- 2026-09-16 12:45 UTCVendor advisory
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-14 04:24 UTCEG score recompute
- 2026-09-14 04:24 UTCVendor advisory
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-13 15:59 UTCVendor advisory
- 2026-09-13 03:09 UTCEG score recompute
- 2026-09-13 03:09 UTCVendor advisory
- 2026-09-12 10:08 UTCVendor advisory
- 2026-09-11 21:42 UTCEG score recompute
- 2026-09-11 21:42 UTCVendor advisory
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-11 09:17 UTCEG score recompute
- 2026-09-11 09:17 UTCVendor advisory
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-09 11:46 UTCEG score recompute
- 2026-09-09 11:46 UTCVendor advisory
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-07 22:47 UTCEG score recompute
- 2026-09-07 22:47 UTCVendor advisory
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-06 11:27 UTCVendor advisory
- 2026-09-05 21:44 UTCEG score recompute
- 2026-09-05 21:44 UTCVendor advisory
- 2026-09-05 09:19 UTCEG score recompute
- 2026-09-05 09:19 UTCVendor advisory
- 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-02 01:01 UTCEG score recompute
- 2026-09-02 01:01 UTCVendor advisory
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownMaven:io.netty:netty-codec-http
Same vendor
10 shownredhat:RHSA-2026:47172 · redhat:RHSA-2026:50846 · redhat:RHSA-2026:62260
Frequently asked(5)
What is CVE-2026-55833?
When was the CVE record for CVE-2026-55833 published?
Is CVE-2026-55833 actively exploited?
What is the CVSS score of CVE-2026-55833?
How do I remediate CVE-2026-55833?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55833
Is Your Infrastructure Affected by CVE-2026-55833?
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