Io.netty/netty-codec-http2: netty: http/2 hpackencoder dos with large table size
Summary
| CVE | CVE-2026-93492 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-18 13:18:38 UTC |
| Updated | 2026-09-18 19:06:08 UTC |
| Description | A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS). |
Risk And Classification
Primary CVSS: v3.1 5.3 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS: 0.003010000 probability, percentile 0.229550000 (date 2026-09-20)
Problem Types: CWE-1035 | CWE-1035 CWE-1035
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat AMQ Broker 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Apache Camel 4 For Quarkus 3 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Apache Camel For Spring Boot 4 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Apicurio Registry 3 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Debezium 3 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Keycloak | Not specified | Not specified |
| CNA | Red Hat | Red Hat Build Of Quarkus | Not specified | Not specified |
| CNA | Red Hat | Red Hat Data Grid 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Fuse 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat JBoss Enterprise Application Platform 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat JBoss Enterprise Application Platform 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Single Sign-On 7 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-93492 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-09-10T00:41:18.000Z | Reported to Red Hat. |
| CNA | 2026-09-10T00:41:18.000Z | Made public. |
Workarounds
CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
There are currently no legacy QID mappings associated with this CVE.