ALAS2023-2026-1813

References: CVE-2026-33814  CVE-2026-81849 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a value of 0. (CVE-2026-33814)

Improper limitation of a pathname to a restricted directory in the aws:downloadContent plugin in amazon-ssm-agent before 3.3.4515.0 might allow an authenticated remote user whose ssm:SendCommand permission is restricted to the AWS-DownloadContent document, to write arbitrary files outside the intended download directory with root privileges, via crafted object keys in the S3 source the document is directed to retrieve. This issue may lead to arbitrary code execution as root if specific sensitive files are overwritten.

To remediate this issue, customers should upgrade amazon-ssm-agent to version 3.3.4515.0 or later. (CVE-2026-81849)

Issue Correction:
Run dnf update amazon-ssm-agent --releasever 2023.12.20260608 or dnf update --advisory ALAS2023-2026-1813 --releasever 2023.12.20260608 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation

New Packages:

aarch64:
    amazon-ssm-agent-3.3.4515.0-1.amzn2023.aarch64

src:
    amazon-ssm-agent-3.3.4515.0-1.amzn2023.src

x86_64:
    amazon-ssm-agent-3.3.4515.0-1.amzn2023.x86_64

Changelog:

2026-10-14: CVE-2026-81849 was added to this advisory.