Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| haproxy | haproxy | ≤ 3.4.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | haproxy | 3.2.20-1 | — |
| Debian 13 | haproxy | No fix yet | — |
| Debian 12 | haproxy | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | haproxy | 3.2.9-1ubuntu2.2 | — |
| Ubuntu 25.10 | haproxy | 3.0.12-0ubuntu0.25.10.5 | — |
| Ubuntu 24.04 LTS | haproxy | 2.8.16-0ubuntu0.24.04.3 | — |
| Ubuntu 22.04 LTS | haproxy | 2.4.30-0ubuntu0.22.04.2 | — |
| Ubuntu 20.04 LTS | haproxy | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | haproxy | No fix yet | — |
| Ubuntu Pro 16.04 LTS | haproxy | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | haproxy | 3.0.5-6.el10_2.2 | RHSA-2026:55679 |
| RHEL 9 | haproxy | 2.8.14-3.el9_8.2 | RHSA-2026:55772 |
| RHEL 8 | haproxy | 1.8.27-5.el8_10.2 | RHSA-2026:55859 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | haproxy | 3.0.5-4.el10_0.3 | RHSA-2026:55800 |
| RHEL 9.6 EUS | haproxy | 2.4.22-4.el9_6.3 | RHSA-2026:55803 |
| RHEL 9.4 E4S | haproxy | 2.4.22-3.el9_4.3 | RHSA-2026:55801 |
| RHEL 9.2 E4S | haproxy | 2.4.17-6.el9_2.5 | RHSA-2026:55802 |
| RHEL 8.8 TUS | haproxy | 1.8.27-5.el8_8.2 | RHSA-2026:55860 |
| RHEL 8.8 E4S | haproxy | 1.8.27-5.el8_8.2 | RHSA-2026:55860 |
| RHEL 8.6 EUS Long Life | haproxy | 1.8.27-4.el8_6.2 | RHSA-2026:55862 |
| RHEL 8.6 AUS | haproxy | 1.8.27-4.el8_6.2 | RHSA-2026:55862 |
| RHEL 8.4 EUS Long Life | haproxy | 1.8.27-2.el8_4.2 | RHSA-2026:55861 |
| RHEL 8.4 AUS | haproxy | 1.8.27-2.el8_4.2 | RHSA-2026:55861 |
| Red Hat Hardened Images 1 | haproxy | 3.0.25-0.1.hum1 | RHSA-2026:35453 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | haproxy | 3.0.5-6.el10_2.2 | ALSA-2026:55679 |
| AlmaLinux 9 | haproxy | 2.8.14-3.el9_8.2 | ALSA-2026:55772 |
| AlmaLinux 8 | haproxy | 1.8.27-5.el8_10.2 | ALSA-2026:55859 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | haproxy | 3.0.5-6.el10_2.2 | RLSA-2026:55679 |
| Rocky Linux 9 | haproxy | 2.8.14-3.el9_8.2 | RLSA-2026:55772 |
| Rocky Linux 8 | haproxy | 1.8.27-5.el8_10.2 | RLSA-2026:55859 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | haproxy | 2.8.11+git0.01c1056a4-150600.3.15.1 | SUSE-SU-2026:2652-1 |
| SLES 15 SP6 | haproxy | 2.8.11+git0.01c1056a4-150600.3.15.1 | SUSE-SU-2026:2652-1 |
| SLES 15 SP5 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 | SUSE-SU-2026:2651-1 |
| SLES 15 SP4 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 | SUSE-SU-2026:2651-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 | SUSE-SU-2026:22587-1 |
| SLES 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 | SUSE-SU-2026:22557-1 |
| SLE Micro 6.2 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 | SUSE-SU-2026:22544-1 |
| SLE Micro 6.1 | haproxy | 2.8.11+git0.01c1056a4-slfo.1.1_4.1 | SUSE-SU-2026:22663-1 |
| SLE Micro 6.0 | haproxy | 2.8.11+git0.01c1056a4-4.1 | SUSE-SU-2026:22515-1 |
| SLE Micro 5.5 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 | SUSE-SU-2026:2651-1 |
| SLE Micro 5.4 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 | SUSE-SU-2026:2651-1 |
| SLE Micro 5.3 | haproxy | 2.4.22+git0.f8e3218e2-150400.3.28.1 | SUSE-SU-2026:2651-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | haproxy | 3.4.0+git31.fc300e9f2-1.1 | openSUSE-SU-2026:11090-1 |
| openSUSE Leap 16.0 | haproxy | 3.2.21+git0.dbe43be37-160000.1.1 | openSUSE-SU-2026:21245-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | haproxy | 3.0.23-2.amzn2023.0.1 | ALAS2023-2026-1915 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | haproxy | 2.9.11-7 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | haproxy | 3.0.5-6.el10_2.2 | ELSA-2026-55679 |
| Oracle Linux 9 | haproxy | 2.8.14-3.el9_8.2 | ELSA-2026-55772 |
| Oracle Linux 8 | haproxy | 1.8.27-5.el8_10.2 | ELSA-2026-55859 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | haproxy-3.2 | 3.2.20-r0 | — |
| Wolfi rolling | haproxy-3.3 | 3.3.11-r0 | — |
Advisories 31
- WID-SEC-2026-2012 HAProxy: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- ALSA-2026:55772 Important: haproxy security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:55679 Important: haproxy security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:55859 Important: haproxy security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:55861 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55862 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55859 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55860 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55803 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55801 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55802 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55800 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55679 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:55772 Red Hat Security Advisory: haproxy security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:35453 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RLSA-2026:55679 Important: haproxy security update Rocky Linux Security Advisories · Aug 18, 2026
- RLSA-2026:55859 Important: haproxy security update Rocky Linux Security Advisories · Aug 18, 2026
- RLSA-2026:55772 Important: haproxy security update Rocky Linux Security Advisories · Aug 18, 2026
- ELSA-2026-55679 Important: haproxy security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Aug 17, 2026
- ELSA-2026-55772 Important: haproxy security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 17, 2026
- ELSA-2026-55859 Important: haproxy security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 17, 2026
- SUSE-SU-2026:22663-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 21, 2026
- SUSE-SU-2026:22587-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 15, 2026
- SUSE-SU-2026:22557-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 15, 2026
- SUSE-SU-2026:22544-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 14, 2026
- SUSE-SU-2026:22515-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 9, 2026
- openSUSE-SU-2026:21245-1 Security update for haproxy SUSE / openSUSE Security Updates · Jul 9, 2026
- ALAS2023-2026-1915 Important: haproxy security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 7, 2026
- SUSE-SU-2026:2651-1 Security update for haproxy SUSE / openSUSE Security Updates · Jun 27, 2026
- SUSE-SU-2026:2652-1 Security update for haproxy SUSE / openSUSE Security Updates · Jun 27, 2026
- openSUSE-SU-2026:11090-1 haproxy-3.4.0+git31.fc300e9f2-1.1 on GA media SUSE / openSUSE Security Updates · Jun 24, 2026
References
- Patch Commit patch
- https://www.vulncheck.com/advisories/haproxy-null-pointer-dereference-in-hpack-dht-insert-function third-party-advisory