Skip to content
Fencer Vulns
medium 6.5

CVE-2026-93566 json

Io.netty/netty-codec-http: netty: http request smuggling due to control characters in the chunk-size line

published 2026-09-18 51 d ago modified 2026-11-06 2 d ago also EUVD-2026-82935

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

A flaw was found in Netty. A remote attacker could exploit this by sending a specially crafted HTTP request that includes control characters within the chunk-size line. This bypasses the intended strict validation, allowing the attacker to inject arbitrary HTTP requests. This vulnerability can lead to HTTP request smuggling, potentially resulting in information disclosure or other unauthorized actions.

Patch / fix

  • Red Hat Red Hat build of Keycloak 26.4 26.4-29, 26.4-30, 26.4.17-2
  • Red Hat Red Hat build of Keycloak 26.6 26.6-24, 26.6.8-2
  • netty-tcnative SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.0.84-150200.3.51.1
  • netty SLE Module for Package Hub 15 SP7 4.1.138-150200.4.56.1

suse advisories SUSE-SU-2026:4391-1

  • netty openSUSE Tumbleweed 4.1.138-1.1

opensuse advisories openSUSE-SU-2026:11882-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-93566 updated cvss 6.5

io.netty/netty-codec-http: Netty: HTTP Request Smuggling due to control characters in the chunk-size line

  • Red Hat AMQ Broker 7 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat AMQ Clients netty-codec-http 4.1.137.Final-redhat-00001 Red Hat build of Apache Camel 4 for Quarkus 3 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat build of Apache Camel for Spring Boot 4 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat build of Apicurio Registry 3 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat Data Grid 8 netty-codec-http 4.1.137.Final-redhat-00001
    affected: workaround, no fix available “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.”
  • Red Hat Fuse 7 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat JBoss Enterprise Application Platform 7 netty-codec-http 4.1.137.Final-redhat-00001 Red Hat Single Sign-On 7 netty-codec-http 4.1.137.Final-redhat-00001
    affected: workaround, no fix planned “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.”
  • Red Hat Build of Debezium 3.6
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:83612
  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-29, rhbk/keycloak-rhel9-operator 26.4-30, rhbk/keycloak-operator-bundle 26.4.17-2
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:95760
  • Red Hat build of Keycloak 26.4.17
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:95759
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-24, rhbk/keycloak-rhel9-operator 26.6-24, rhbk/keycloak-operator-bundle 26.6.8-2
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:95762
  • Red Hat build of Keycloak 26.6.8
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:95761
  • Red Hat build of Quarkus 3.27.5.SP2
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:69470
show 2 more
  • Red Hat build of Quarkus 3.33.3.SP2
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:69440
  • Red Hat JBoss Enterprise Application Platform 8.1
    fixed: vendor fix “See https://github.com/netty/netty/security/advisories/GHSA-rq4j-fc47-9698 for fixed versions and remediation guidance.” RHSA-2026:95887

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
47 d ago

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

  • Red Hat Red Hat Build of Debezium 3.6
  • Red Hat Red Hat build of Keycloak 26.4
  • Red Hat Red Hat build of Keycloak 26.4.17
  • Red Hat Red Hat build of Keycloak 26.6
  • Red Hat Red Hat build of Keycloak 26.6.8
  • Red Hat Red Hat build of Quarkus 3.27.5.SP2
  • Red Hat Red Hat build of Quarkus 3.33.3.SP2
  • Red Hat Red Hat JBoss Enterprise Application Platform 8.1
  • Red Hat Red Hat AMQ Broker 7
  • Red Hat Red Hat AMQ Clients
  • Red Hat Red Hat build of Apache Camel 4 for Quarkus 3
  • Red Hat Red Hat build of Apache Camel for Spring Boot 4
  • Red Hat Red Hat build of Apicurio Registry 3
  • Red Hat Red Hat Data Grid 8
  • Red Hat Red Hat Fuse 7
  • Red Hat Red Hat JBoss Enterprise Application Platform 7
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness
  • CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.