CVE-2026-19643 PUBLISHED

Out-of-bounds read in the Base64 decoder in Amazon aws-sdk-cpp on signed-char platforms

Assigner: AMZN
Reserved: 12.08.2026 Published: 12.08.2026 Updated: 13.08.2026

An out-of-bounds read issue in the Base64 decoder in Amazon aws-sdk-cpp before 1.11.862, on some platforms, might allow a remote authenticated user to crash an application that processes crafted Base64-encoded input.

To remediate this issue, users should upgrade to version 1.11.862.

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	AWS
Product	aws-sdk-cpp
Versions	Default: unaffected affected from 0 to 1.11.861 (incl.)

Credits

University of Manchester finder

References

Problem Types

CWE-125 Out-of-bounds read CWE

Impacts

CAPEC-540 Overread Buffers