CVE-2026-73548

Public on 2026-09-08

Modified on 2026-09-08

Description

Fixed cross-user response poisoning involving generic, non-WebSocket HTTP upgrades, where request payload sent before an upgrade was accepted could contaminate a shared upstream connection.

Severity

Important

See what this means

CVSS v3 Base Score

7.5

See breakdown

Affected Packages

Platform	Package	Release Date	Advisory	Status
Amazon Linux 2 - Ecs Extra	ecs-service-connect-agent	2026-09-14	ALAS2ECS-2026-137	Fixed
Amazon Linux 2023	ecs-service-connect-agent	2026-09-14	ALAS2023-2026-2149	Fixed

CVSS Scores

	Score Type	Score	Vector
Amazon Linux	CVSSv3	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

FAQs regarding Amazon Linux ALAS/CVE Severity Red Hat: CVE-2026-73548 Mitre: CVE-2026-73548