CVE-2026-55204

HighCVSS 7.5/10Last modified Oct 26, 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.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-476

Affected software

Vendor	Product	Versions
haproxy	haproxy	<= 3.4.0

References

Timeline

Published: Jun 18, 2026
Last modified: Oct 26, 2026
NVD status: Analyzed

Related CVEs from 2026

CVE-2026-552055.3Hermes WebUI before 0.51.468 contains a resource exhaustion vulnerability in the unauthenticated POST /api/onboarding/oauth/start endpoint t CVE-2026-552068.7py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, P CVE-2026-552078.8Pimcore is an Open Source Data & Experience Management Platform. Prior to 2025.4.6 and 2026.1.6, an unauthenticated attacker who knows a val CVE-2026-552087.7Pimcore Studio Backend Bundle is the backend bundle for Pimcore Studio. Prior to 2025.4.6 and 2026.1.6, an authenticated user can extract th CVE-2026-552099.8resdata is software for reading and writing result files from the Eclipse reservoir simulator. Prior to 6.2.9, resdata insufficiently valida CVE-2026-552107.4Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's Us CVE-2026-552119.8Surfio is a library for reading and writing surface files. Prior to 0.0.19, surfio does not correctly validate size fields in IRAP files, le CVE-2026-552127.1Pimcore is an Open Source Data & Experience Management Platform. Prior to 2025.4.6 and 2026.1.6, the Studio API class definition creation en CVE-2026-552137.5h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit edd7a120bfc4af11ac0cbebce2a43cc1f93f9af1, when h2o proce CVE-2026-552148.5GLPI is a free asset and IT management software package. From 11.0.6 until 11.0.8, an authenticated technician can store active markup in su CVE-2026-552157.5MariaDB Connector/Node.js is used to connect applications developed on Node.js to MariaDB and MySQL databases. Prior to versions 3.3.3, 3.4.CVE-2026-552175.3GLPI is a free asset and IT management software package. From 0.85 until 10.0.26 and 11.0.8, a low-privileged authenticated user can create,