Disclosure summary
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.
Source-reported weakness categories
CWE-476
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-55204
Open original source · Updated Oct 08, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| haproxy | haproxy | * {"versionStartIncluding":"3.3","versionEndExcluding":"3.4.1"} |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Patch
- www.vulncheck.com — Third Party Advisory
PUBLISHED 2026-06-18T13:16:34-04:00
MODIFIED 2026-10-08T13:13:02-04:00
INGESTED 2026-10-10T20:50:35-04:00