Out-of-bounds write in the Base64 decoder in Amazon aws-sdk-cpp (CVE-2026-19642) | HOL Guard CVE

Medium · CVSS 5.9CVE-2026-19642

Out-of-bounds write in the Base64 decoder in Amazon aws-sdk-cpp

Answer in brief

CVE-2026-19642 records a Medium severity (CVSS 5.9) vulnerability in Out-of-bounds write in the Base64 decoder in Amazon aws-sdk-cpp. The current sources do not mark it as known exploited. The current feed maps AWS/aws-sdk-cpp (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 12, 2026Updated Aug 18, 2026Source checked Sep 27, 2026First seen by HOL Aug 12, 2026Material review Aug 18, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.9
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps AWS/aws-sdk-cpp (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:amazon:aws_software_development_kit::::::c\+\+::*	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
AWS/aws-sdk-cppgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for AWS/aws-sdk-cpp.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 12, 2026

Sources and claim methodology

Upstream source description

An out-of-bounds write issue in the Base64 decoder in Amazon aws-sdk-cpp before 1.11.862 might allow a remote authenticated user to cause a crash or heap memory corruption in an application that processes crafted Base64-encoded input. To remediate this issue, users should upgrade to version 1.11.862.

Quoted source text, attributed separately from HOL analysis.