CVE-2026-33555
4.0 · MEDIUMOverview
CVE-2026-33555 is a medium-severity vulnerability affecting haproxy haproxy. It was published on April 13, 2026 and has a CVSS 3.1 base score of 4.0 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.0, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6.
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 | >= 2.6.0, < 3.3.6 | Affected |
References
Frequently Asked Questions
What is CVE-2026-33555?
CVE-2026-33555 is a medium-severity vulnerability affecting haproxy haproxy. It was published on April 13, 2026 and has a CVSS 3.1 base score of 4.0 (MEDIUM).
How severe is CVE-2026-33555?
This vulnerability has a CVSS 3.1 base score of 4.0, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-33555?
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-2026-33555?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-33555 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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