p PatchFirst

CVE-2026-56853

CVE-2026-56853 · Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check 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 a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.

CVSS 7.5 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • net/http

    Versions
    • ≥ 0, < 1.25.13: Affected (semver)
    • ≥ 1.26.0-0, < 1.26.6: Affected (semver)
    • ≥ 1.27.0-0, < 1.27.0-rc.3: Affected (semver)

    Update to 1.25.13; Update to 1.26.6; Update to 1.27.0-rc.3

  • 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~rc2-1
    • 1.26~rc3-1
    • 1.26~rc3-2
    Affected ranges
    • ECOSYSTEM: < 1.26.6-1

    Update to 1.26.6-1

  • golang-1.27 Debian:14

    Versions
    • 1.27~rc1-1
    • 1.27~rc2-1
    Affected ranges
    • ECOSYSTEM: < 1.27~rc3-1

    Update to 1.27~rc3-1

  • 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

Check your server →