CVE-2026-55204
HIGH EPSS 34.5%
Published Jun 18, 20261w ago · Modified Jun 22, 20261w ago
8.7 CVSS 4.0
Published Jun 18, 2026 1w ago
Last Modified Jun 22, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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 Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
34.5% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-476 NULL Pointer Dereference Memory Safety
References 2
- github.com https://github.com/haproxy/haproxy/commit/9a6d1fe3f00d86ab4ea6ea6ea0a5d48fc058a513
- vulncheck.com https://www.vulncheck.com/advisories/haproxy-null-pointer-dereference-in-hpack-dht-insert-function
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.