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.
CVSS Details
- CVSS 4.0 Base Score: 8.7 (HIGH)
- CVSS 4.0 Vector: (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade haproxyUpgrade haproxy-debuginfoUpgrade haproxy-debugsource | Jul 8, 2026 | Jun 18, 2026 |
| Redhat_linux | — | Upgrade haproxyUpgrade haproxy-debuginfoNo solution existsUpgrade haproxy-debugsource | Jul 20, 2026 | Jun 18, 2026 |
| Rocky_linux | — | Upgrade haproxyUpgrade haproxy-debugsourceUpgrade haproxy-debuginfo | Aug 20, 2026 | Aug 18, 2026 |
| Ubuntu | — | Upgrade haproxy | Jun 23, 2026 | Jun 22, 2026 |
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