GHSA-6v7p-g79w-8964 (HIGH): detected in Lambda Docker Images.

[the-lambda-watchdog]

CVE Details

CVE ID	Severity	Affected Package	Installed Version	Fixed Version	Date Published	Date of Scan
GHSA-6v7p-g79w-8964	HIGH	msgpack	1.1.2	1.2.1	2026-06-19T21:42:55Z	2026-08-13T10:18:42.129576392Z

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Affected Docker Images

Image Name	SHA
public.ecr.aws/lambda/python:3.13	public.ecr.aws/lambda/python@sha256:4763641547a2bd881065e0b196d2887369876e524561b12519e2662fde3361e5

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Description

Impact

If the Unpacker is used repeatedly after an error occurs, the process may crash with a SEGV.

If the Unpacker is used repeatedly to unpack untrusted input from external sources, it may be vulnerable to a DoS attack.

Patches

v1.2.1

Workarounds

Users should create a new Unpacker instead of reusing the same Unpacker after an error occurs.

Applying the above patch can prevent SEGV, but reusing the Streaming Unpacker after it has encountered an error will not yield correct data. If an error occurs during Streaming Unpacking, the Stream and Streaming Unpacker should be discarded.

Therefore, this is not just a workaround but the correct solution. The above patch only prevents crashes from incorrect usage.

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Remediation Steps

• Update the affected package msgpack from version 1.1.2 to 1.2.1.

About this issue

• This issue may not contain all the information about the CVE nor the images it affects.
• This issue will not be updated with new information and the list of affected images may have changed since the creation of this issue.
• For more, visit Lambda Watchdog.
• This issue was created automatically by Lambda Watchdog.