CVE-2026-55204
Fixed in a distro release EPSS <1%CVSS 7.5
HAProxy through 3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack_dht_insert() within src/hpack-tbl.c that fails to validate the return value of hpack_dht_defrag() when the memory pool is exhausted. An attacker can trigger HPACK dynamic table insertions under memory pressure to dereference a NULL pointer and crash HAProxy worker processes, causing denial of service.
Products: haproxy
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux 10 | haproxy | 3.0.5-6.el10_2.2 |
| AlmaLinux 8 | haproxy | 1.8.27-5.el8_10.2 |
| AlmaLinux 9 | haproxy | 2.8.14-3.el9_8.2 |
| Chainguard | haproxy-2.4 | 2.4.36-r0 |
| Chainguard | haproxy-2.6 | 2.6.31-r0 |
| Chainguard | haproxy-2.8 | 2.8.26-r0 |
| Chainguard | haproxy-3.0 | 3.0.24-r0 |
| Chainguard | haproxy-3.1 | no fix |
| Chainguard | haproxy-3.2 | 3.2.20-r0 |
| Chainguard | haproxy-3.3 | 3.3.11-r0 |
| Debian 12 | haproxy | no fix |
| Debian 13 | haproxy | no fix |
| Debian 14 | haproxy | 3.2.20-1 |
| Red Hat Enterprise Linux 10.2 | haproxy | 0:3.0.5-6.el10_2.2 |
| Red Hat Enterprise Linux 10.2 | haproxy-debuginfo | 0:3.0.5-6.el10_2.2 |
| Red Hat Enterprise Linux 10.2 | haproxy-debugsource | 0:3.0.5-6.el10_2.2 |
| Red Hat Enterprise Linux 8 | haproxy | 0:1.8.27-5.el8_10.2 |
| Red Hat Enterprise Linux 8 | haproxy-debuginfo | 0:1.8.27-5.el8_10.2 |
| Red Hat Enterprise Linux 8 | haproxy-debugsource | 0:1.8.27-5.el8_10.2 |
| Red Hat Enterprise Linux 9 | haproxy | 0:2.8.14-3.el9_8.2 |
| Red Hat Enterprise Linux 9 | haproxy-debuginfo | 0:2.8.14-3.el9_8.2 |
| Red Hat Enterprise Linux 9 | haproxy-debugsource | 0:2.8.14-3.el9_8.2 |
| Red Hat Enterprise Linux eus 10.0 | haproxy | 0:3.0.5-4.el10_0.3 |
| Red Hat Enterprise Linux eus 10.0 | haproxy-debuginfo | 0:3.0.5-4.el10_0.3 |
| Red Hat Enterprise Linux eus 10.0 | haproxy-debugsource | 0:3.0.5-4.el10_0.3 |
| Red Hat hummingbird 1 | haproxy | 0:3.0.25-0.1.hum1 |
| Red Hat rhel aus 8.4 | haproxy | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel aus 8.4 | haproxy-debuginfo | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel aus 8.4 | haproxy-debugsource | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel aus 8.6 | haproxy | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel aus 8.6 | haproxy-debuginfo | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel aus 8.6 | haproxy-debugsource | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel e4s 8.8 | haproxy | 0:1.8.27-5.el8_8.2 |
| Red Hat rhel e4s 8.8 | haproxy-debuginfo | 0:1.8.27-5.el8_8.2 |
| Red Hat rhel e4s 8.8 | haproxy-debugsource | 0:1.8.27-5.el8_8.2 |
| Red Hat rhel e4s 9.2 | haproxy | 0:2.4.17-6.el9_2.5 |
| Red Hat rhel e4s 9.2 | haproxy-debuginfo | 0:2.4.17-6.el9_2.5 |
| Red Hat rhel e4s 9.2 | haproxy-debugsource | 0:2.4.17-6.el9_2.5 |
| Red Hat rhel e4s 9.4 | haproxy | 0:2.4.22-3.el9_4.3 |
| Red Hat rhel e4s 9.4 | haproxy-debuginfo | 0:2.4.22-3.el9_4.3 |
| Red Hat rhel e4s 9.4 | haproxy-debugsource | 0:2.4.22-3.el9_4.3 |
| Red Hat rhel eus 9.6 | haproxy | 0:2.4.22-4.el9_6.3 |
| Red Hat rhel eus 9.6 | haproxy-debuginfo | 0:2.4.22-4.el9_6.3 |
| Red Hat rhel eus 9.6 | haproxy-debugsource | 0:2.4.22-4.el9_6.3 |
| Red Hat rhel eus long life 8.4 | haproxy | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel eus long life 8.4 | haproxy-debuginfo | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel eus long life 8.4 | haproxy-debugsource | 0:1.8.27-2.el8_4.2 |
| Red Hat rhel eus long life 8.6 | haproxy | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel eus long life 8.6 | haproxy-debuginfo | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel eus long life 8.6 | haproxy-debugsource | 0:1.8.27-4.el8_6.2 |
| Red Hat rhel tus 8.8 | haproxy | 0:1.8.27-5.el8_8.2 |
| Red Hat rhel tus 8.8 | haproxy-debuginfo | 0:1.8.27-5.el8_8.2 |
| Red Hat rhel tus 8.8 | haproxy-debugsource | 0:1.8.27-5.el8_8.2 |
| Rocky Linux 10 | haproxy | 0:3.0.5-6.el10_2.2 |
| Rocky Linux 8 | haproxy | 0:1.8.27-5.el8_10.2 |
| Rocky Linux 9 | haproxy | 0:2.8.14-3.el9_8.2 |
| SUSE Linux Enterprise High Availability Extension 15 SP4 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP5 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP6 | haproxy | 2.8.11+git0.01c1056a4-150600.3.15.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | haproxy | 2.8.11+git0.01c1056a4-150600.3.15.1 |
| SUSE Linux Enterprise High Availability Extension 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 |
| SUSE Linux Enterprise Micro 5.3 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 |
| SUSE Linux Enterprise Micro 5.4 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 |
| SUSE Linux Enterprise Micro 5.5 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 |
| SUSE Linux Micro 6.0 | haproxy | 2.8.11+git0.01c1056a4-4.1 |
| SUSE Linux Micro 6.1 | haproxy | 2.8.11+git0.01c1056a4-slfo.1.1_4.1 |
| SUSE Linux Micro 6.2 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 |
| Ubuntu 20.04 LTS | haproxy | no fix |
| Ubuntu 22.04 LTS | haproxy | 2.4.30-0ubuntu0.22.04.2 |
| Ubuntu 24.04 LTS | haproxy | 2.8.16-0ubuntu0.24.04.3 |
| Ubuntu 25.10 | haproxy | 3.0.12-0ubuntu0.25.10.5 |
| Ubuntu 26.04 LTS | haproxy | 3.2.9-1ubuntu2.2 |
| Ubuntu Pro 16.04 LTS | haproxy | no fix |
| Ubuntu Pro 18.04 LTS | haproxy | no fix |
| Wolfi | haproxy-3.2 | 3.2.20-r0 |
| Wolfi | haproxy-3.3 | 3.3.11-r0 |
| openSUSE Leap 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 |
| openSUSE Tumbleweed | haproxy | 3.4.0+git31.fc300e9f2-1.1 |