CVE-2026-55204
HAProxy - NULL Pointer Dereference in hpack_dht_insert Function
- State
- Published
- Severity
- 8.7 High
- Published
- Jun 18, 2026
- Updated
- Jul 14, 2026
- Reserved
- Jun 16, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-476 NULL Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
haproxyhaproxy |
|
References
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