CVE-2026-55204
7.5 · HIGHOverview
CVE-2026-55204 is a high-severity vulnerability affecting haproxy haproxy. It was published on June 18, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from haproxy. Update haproxy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| haproxy | haproxy | 0 | Affected |
Frequently Asked Questions
What is CVE-2026-55204?
CVE-2026-55204 is a high-severity vulnerability affecting haproxy haproxy. It was published on June 18, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-55204?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-55204?
Check the references section for vendor advisories and patches from haproxy. Update haproxy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-55204?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-55204 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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