CVE-2026-33555

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.30% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 22.1% of scored records. A rank, not a probability.

NVD base score

5.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-29.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-13 00:00Z4 MO AGO

Last updated

2026-04-22 18:43Z4 MO AGO

Reserved

2026-03-22

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 4.0)

CNA CVSS vector

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

Weaknesses

• CWE-130Improper Handling of Length Parameter InconsistencyBase

Data version

5.2

Document digest

36d27332f6124a90e28f1be6d04e39073c7f9907e04c7e3d8531b1b45193f750

• www.haproxy.orghttps://www.haproxy.org
• www.haproxy.comhttps://www.haproxy.com/documentation/haproxy-aloha/changelog/
• github.comhttps://github.com/haproxy/haproxy/commit/05a295441c621089ffa4318daf0dbca2dd756a84
• www.mail-archive.comhttps://www.mail-archive.com/haproxy@formilux.org/msg46752.html
• r3verii.github.iohttps://r3verii.github.io/cve/2026/04/14/haproxy-h3-standalone-fin-smuggling.html