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CVE-2026-42581

CVE-2026-42581 · Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS 5.8 · Medium · EPSS 0.6% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • netty

    Versions
    • >= 4.2.0.Alpha1, < 4.2.13.Final: Affected
    • < 4.1.133.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
    Affected ranges
    • ECOSYSTEM: < 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1

    Update to 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.0.34-1ubuntu0.1~esm4

    Update to 1:4.0.34-1ubuntu0.1~esm4

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.1.7-4ubuntu0.1+esm6

    Update to 1:4.1.7-4ubuntu0.1+esm6

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.1.45-1ubuntu0.1~esm6

    Update to 1:4.1.45-1ubuntu0.1~esm6

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.1.48-4+deb11u2ubuntu0.1+esm3

    Update to 1:4.1.48-4+deb11u2ubuntu0.1+esm3

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.1.48-9ubuntu0.1+esm3

    Update to 1:4.1.48-9ubuntu0.1+esm3

  • 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
    Affected ranges
    • ECOSYSTEM: < 1:4.1.48-16ubuntu0.1~esm2

    Update to 1:4.1.48-16ubuntu0.1~esm2

Original sources

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