Critical (9.8). EPSS 4.0% chance of exploitation in the next 30 days.
The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII 0x0), aka Intermediary Encapsulation Attacks.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.0% chance of exploitation in the next 30 days; higher than 90% of CVEs (scores of 2026-10-31)