CVE-2026-33871
CVE-2026-33871 · Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server's lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.
CVSS 8.7 · High · EPSS 1.1%
- Published
- Updated
Stack: system
Affected products and versions
netty
- Versions
- < 4.1.132.Final: Affected
- >= 4.2.0.Alpha1, < 4.2.10.Final: Affected
No fix published
netty Debian:12
- Versions
- 1:4.1.48-10
- 1:4.1.48-11
- 1:4.1.48-12
- 1:4.1.48-13
- 1:4.1.48-14
- 1:4.1.48-15
- 1:4.1.48-16
- 1:4.1.48-7
- 1:4.1.48-7+deb12u1
- 1:4.1.48-7+deb12u2
- 1:4.1.48-8
- 1:4.1.48-9
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Debian:13
- Versions
- 1:4.1.48-10
- 1:4.1.48-10+deb13u1
- 1:4.1.48-11
- 1:4.1.48-12
- 1:4.1.48-13
- 1:4.1.48-14
- 1:4.1.48-15
- 1:4.1.48-16
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Debian:14
- Versions
- 1:4.1.48-10
- 1:4.1.48-11
- 1:4.1.48-12
- 1:4.1.48-13
- 1:4.1.48-14
- 1:4.1.48-15
- 1:4.1.48-16
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:14.04:LTS
- Versions
- 1:3.2.6.Final-2
- 1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1
- 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:16.04:LTS
- Versions
- 1:3.2.6.Final-2
- 1:4.0.32-1
- 1:4.0.33-1
- 1:4.0.34-1
- 1:4.0.34-1ubuntu0.1~esm1
- 1:4.0.34-1ubuntu0.1~esm2
- 1:4.0.34-1ubuntu0.1~esm3
- 1:4.0.34-1ubuntu0.1~esm4
- 1:4.0.34-1ubuntu0.1~esm5
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:18.04:LTS
- Versions
- 1:4.1.7-4
- 1:4.1.7-4ubuntu0.1~esm1
- 1:4.1.7-4ubuntu0.1
- 1:4.1.7-4ubuntu0.1+esm1
- 1:4.1.7-4ubuntu0.1+esm2
- 1:4.1.7-4ubuntu0.1+esm3
- 1:4.1.7-4ubuntu0.1+esm4
- 1:4.1.7-4ubuntu0.1+esm5
- 1:4.1.7-4ubuntu0.1+esm6
- 1:4.1.7-4ubuntu0.1+esm7
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:20.04:LTS
- Versions
- 1:4.1.33-1
- 1:4.1.33-2
- 1:4.1.33-3
- 1:4.1.45-1
- 1:4.1.45-1ubuntu0.1~esm1
- 1:4.1.45-1ubuntu0.1~esm2
- 1:4.1.45-1ubuntu0.1~esm3
- 1:4.1.45-1ubuntu0.1~esm4
- 1:4.1.45-1ubuntu0.1~esm6
- 1:4.1.45-1ubuntu0.1~esm7
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:22.04:LTS
- Versions
- 1:4.1.48-4
- 1:4.1.48-4+deb11u1build0.22.04.1
- 1:4.1.48-4+deb11u2build0.22.04.1
- 1:4.1.48-4+deb11u2ubuntu0.1~esm1
- 1:4.1.48-4+deb11u2ubuntu0.1~esm2
- 1:4.1.48-4+deb11u2ubuntu0.1
- 1:4.1.48-4+deb11u2ubuntu0.1+esm1
- 1:4.1.48-4+deb11u2ubuntu0.1+esm3
- 1:4.1.48-4+deb11u2ubuntu0.2
- 1:4.1.48-4+deb11u2ubuntu0.2+esm1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:24.04:LTS
- Versions
- 1:4.1.48-7
- 1:4.1.48-8
- 1:4.1.48-9
- 1:4.1.48-9ubuntu0.1~esm1
- 1:4.1.48-9ubuntu0.1~esm2
- 1:4.1.48-9ubuntu0.1
- 1:4.1.48-9ubuntu0.1+esm1
- 1:4.1.48-9ubuntu0.1+esm3
- 1:4.1.48-9ubuntu0.2
- 1:4.1.48-9ubuntu0.2+esm1
- 1:4.1.48-9ubuntu0.2+esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:25.10
- Versions
- 1:4.1.48-10
- 1:4.1.48-10ubuntu0.25.10.1
- 1:4.1.48-10ubuntu0.25.10.2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:26.10
- Versions
- 1:4.1.48-16
- 1:4.1.48-16ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
netty Ubuntu:Pro:26.04:LTS
- Versions
- 1:4.1.48-10
- 1:4.1.48-11
- 1:4.1.48-12
- 1:4.1.48-13
- 1:4.1.48-14
- 1:4.1.48-16
- 1:4.1.48-16ubuntu0.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
Original sources
- https://github.com/netty/netty/security/advisories/GHSA-w9fj-cfpg-grvv
- https://access.redhat.com/security/cve/CVE-2026-33871
- https://bugzilla.redhat.com/show_bug.cgi?id=2452456
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33871.json
- https://access.redhat.com/errata/RHSA-2026:18054
- https://access.redhat.com/errata/RHSA-2026:17789
- https://access.redhat.com/errata/RHSA-2026:18055
- https://access.redhat.com/errata/RHSA-2026:14276
- https://access.redhat.com/errata/RHSA-2026:14272
- https://access.redhat.com/errata/RHSA-2026:8509
- https://access.redhat.com/errata/RHSA-2026:8159
- https://access.redhat.com/errata/RHSA-2026:22619
- https://access.redhat.com/errata/RHSA-2026:18059
- https://access.redhat.com/errata/RHSA-2026:10184
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:10175
- https://access.redhat.com/errata/RHSA-2026:17668
- https://access.redhat.com/errata/RHSA-2026:7109
- https://access.redhat.com/errata/RHSA-2026:7380
- https://access.redhat.com/errata/RHSA-2026:34608
- https://access.redhat.com/errata/RHSA-2026:13571
- https://nvd.nist.gov/vuln/detail/CVE-2026-33871