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CVE-2026-94439

CVE-2026-94439 · HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http

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

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP.

CVSS 7.5 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • net/http

    Versions
    • ≥ 0, < 1.26.9: Affected (semver)
    • ≥ 1.27.0-0, < 1.27.2: Affected (semver)

    Update to 1.26.9; Update to 1.27.2

  • golang-1.19 Debian:12

    Versions
    • 1.19.10-1
    • 1.19.10-2
    • 1.19.11-1
    • 1.19.12-1
    • 1.19.12-2
    • 1.19.12-2~bpo11+1
    • 1.19.12-2~bpo12+1
    • 1.19.13-1
    • 1.19.13-1~bpo11+1
    • 1.19.13-1~bpo12+1
    • 1.19.8-2
    • 1.19.9-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.24 Debian:13

    Versions
    • 1.24.12-1
    • 1.24.13-1
    • 1.24.13-2
    • 1.24.4-1
    • 1.24.4-2
    • 1.24.4-3
    • 1.24.4-4
    • 1.24.7-1
    • 1.24.8-1
    • 1.24.9-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.26 Debian:14

    Versions
    • 1.26.0-1
    • 1.26.1-1
    • 1.26.2-1
    • 1.26.2-2
    • 1.26.2-3
    • 1.26.3-1
    • 1.26.3-1~bpo13+1
    • 1.26.3-2
    • 1.26.3-2~bpo13+1
    • 1.26.4-1
    • 1.26.4-1~bpo13+1
    • 1.26.5-1
    • 1.26.5-1~bpo13+1
    • 1.26.6-1
    • 1.26.6-2
    • 1.26.7-1
    • 1.26.7-1~bpo13+1
    • 1.26.8-1
    • 1.26.8-1~bpo13+1
    • 1.26.8-2
    • 1.26~rc2-1
    • 1.26~rc3-1
    • 1.26~rc3-2
    Affected ranges
    • ECOSYSTEM: < 1.26.9-1

    Update to 1.26.9-1

  • golang-1.27 Debian:14

    Versions
    • 1.27.0-1
    • 1.27.0-1~bpo13+1
    • 1.27.1-1
    • 1.27.1-2
    • 1.27.1-2~bpo13+1
    • 1.27~rc1-1
    • 1.27~rc2-1
    • 1.27~rc3-1
    Affected ranges
    • ECOSYSTEM: < 1.27.2-1

    Update to 1.27.2-1

  • golang-1.10 Ubuntu:14.04:LTS

    Versions
    • 1.10.4-2ubuntu1~14.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.10 Ubuntu:16.04:LTS

    Versions
    • 1.10.4-2ubuntu1~16.04.1
    • 1.10.4-2ubuntu1~16.04.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.6 Ubuntu:16.04:LTS

    Versions
    • 1.6-0ubuntu1
    • 1.6-0ubuntu2
    • 1.6-0ubuntu3
    • 1.6-0ubuntu4
    • 1.6-0ubuntu5
    • 1.6.1-0ubuntu1
    • 1.6.2-0ubuntu5~16.04
    • 1.6.2-0ubuntu5~16.04.2
    • 1.6.2-0ubuntu5~16.04.3
    • 1.6.2-0ubuntu5~16.04.4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.13 Ubuntu:Pro:16.04:LTS

    Versions
    • 1.13.8-1ubuntu1~16.04.2
    • 1.13.8-1ubuntu1~16.04.3
    • 1.13.8-1ubuntu1~16.04.3+esm2
    • 1.13.8-1ubuntu1~16.04.3+esm3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.18 Ubuntu:Pro:16.04:LTS

    Versions
    • 1.18.1-1ubuntu1~16.04.6
    • 1.18.1-1ubuntu1~16.04.6+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.10 Ubuntu:18.04:LTS

    Versions
    • 1.10~rc1-1
    • 1.10~rc1-1ubuntu1
    • 1.10~rc1-2ubuntu1
    • 1.10~rc2-1ubuntu1
    • 1.10-1ubuntu1
    • 1.10.1-1ubuntu2
    • 1.10.4-2ubuntu1~18.04.1
    • 1.10.4-2ubuntu1~18.04.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.13 Ubuntu:Pro:18.04:LTS

    Versions
    • 1.13.8-1ubuntu1~18.04.2
    • 1.13.8-1ubuntu1~18.04.3
    • 1.13.8-1ubuntu1~18.04.4
    • 1.13.8-1ubuntu1~18.04.4+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.16 Ubuntu:Pro:18.04:LTS

    Versions
    • 1.16.2-0ubuntu1~18.04.2
    • 1.16.2-0ubuntu1~18.04.2+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.18 Ubuntu:Pro:18.04:LTS

    Versions
    • 1.18.1-1ubuntu1~18.04.3
    • 1.18.1-1ubuntu1~18.04.4
    • 1.18.1-1ubuntu1~18.04.4+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.8 Ubuntu:18.04:LTS

    Versions
    • 1.8.3-2ubuntu1
    • 1.8.3-2ubuntu1.18.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.9 Ubuntu:18.04:LTS

    Versions
    • 1.9.1-2ubuntu1
    • 1.9.2-1ubuntu1
    • 1.9.2-3ubuntu1
    • 1.9.3-1ubuntu1
    • 1.9.4-1ubuntu1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.13 Ubuntu:20.04:LTS

    Versions
    • 1.13.1-1ubuntu1
    • 1.13.3-1ubuntu1
    • 1.13.4-1ubuntu1
    • 1.13.5-1ubuntu1
    • 1.13.6-1ubuntu1
    • 1.13.6-2ubuntu1
    • 1.13.7-1ubuntu1
    • 1.13.8-1ubuntu1
    • 1.13.8-1ubuntu1.1
    • 1.13.8-1ubuntu1.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.14 Ubuntu:20.04:LTS

    Versions
    • 1.14~beta1-1
    • 1.14~beta1-2
    • 1.14~rc1-1
    • 1.14-1
    • 1.14.1-1
    • 1.14.2-1
    • 1.14.2-1ubuntu1
    • 1.14.3-2ubuntu2~20.04.1
    • 1.14.3-2ubuntu2~20.04.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.16 Ubuntu:Pro:20.04:LTS

    Versions
    • 1.16.2-0ubuntu1~20.04
    • 1.16.2-0ubuntu1~20.04.1
    • 1.16.2-0ubuntu1~20.04.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.18 Ubuntu:20.04:LTS

    Versions
    • 1.18.1-1ubuntu1~20.04.1
    • 1.18.1-1ubuntu1~20.04.2
    • 1.18.1-1ubuntu1~20.04.3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.20 Ubuntu:20.04:LTS

    Versions
    • 1.20.3-1ubuntu0.1~20.04
    • 1.20.3-1ubuntu0.1~20.04.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.21 Ubuntu:20.04:LTS

    Versions
    • 1.21.1-1~ubuntu20.04.1
    • 1.21.1-1~ubuntu20.04.2
    • 1.21.1-1~ubuntu20.04.3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.17 Ubuntu:22.04:LTS

    Versions
    • 1.17-1ubuntu2
    • 1.17.3-1ubuntu1
    • 1.17.3-1ubuntu2
    • 1.17.13-3ubuntu1
    • 1.17.13-3ubuntu1.2
    • 1.17.13-3ubuntu1.3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • golang-1.18 Ubuntu:22.04:LTS

    Versions
    • 1.18~beta1-0ubuntu1
    • 1.18~beta2-1ubuntu1
    • 1.18~beta2-1ubuntu2
    • 1.18~rc1-1ubuntu1
    • 1.18-1ubuntu1
    • 1.18.1-1ubuntu1
    • 1.18.1-1ubuntu1.1
    • 1.18.1-1ubuntu1.2
    • 1.18.1-1ubuntu1.3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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