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    AWS Security Digest·Week 24 of 2026·Jun 8-14, 2026·5 items

    A Toolchain CVE Storm Meets a SaaS Token Heist

    Four AWS bulletins land in a single week, all in the build and agent toolchain: AgentCore CLI code injection, CDK command injection, s2n-quic memory exhaustion, and a heap double-free in the HTTP client under the C++ and Java SDKs. Meanwhile the Klue breach shows again what stolen OAuth integration tokens are worth.

    In this issue4high1medium

    Highlights

    1 item
    $ tail -f /var/log/aws-security.log
    high/Incident/

    Klue Breach: Stolen OAuth Tokens Expose Customer Salesforce Data

    On June 12, market-intelligence platform Klue discovered unauthorized activity in its integration infrastructure. Attackers had used a compromised legacy credential tied to an integration service to obtain OAuth tokens connecting Klue to customers' third-party platforms, chiefly Salesforce.

    Organizations named in BleepingComputer's reporting include Recorded Future, Tanium, Jamf, Sprout Social, Gong, Insurity, and Huntress. Stolen data includes business contacts, sales communications, and pricing. The newly surfaced Icarus group claimed the attack; Klue says data stored directly in its own platform shows no evidence of compromise.

    The lesson for any AWS-hosted integration hub is the one Snowflake already taught: non-human identities and long-lived integration tokens are the soft perimeter. Inventory them, scope them, and rotate them on a schedule.

    IAM

    CVEs & Vulnerabilities

    4 items
    $ cat /var/reports/CVE_REPORT.txt
    high/CVE/

    CVE-2026-11393: Code Injection in the AWS AgentCore CLI

    CVE-2026-11393Bulletin 2026-040-AWS

    AWS bulletin 2026-040-AWS covers a code injection flaw in the AgentCore CLI's Bedrock Agent import.

    The collaborationInstruction field was not properly escaped during Python code generation, so an authenticated user with bedrock:AssociateAgentCollaborator permission could break out of the generated docstring and inject arbitrary Python that executes when the generated file runs, locally or in the AgentCore Runtime.

    Update to 0.14.2 (or 1.0.0-preview.9 on the preview line).

    Affected
    • AWS AgentCore CLI 0.4.0 - 0.14.1
    • Preview 0.3.0-preview.7.0 - 1.0.0-preview.8
    Fixed In
    • AgentCore CLI 0.14.2
    • Preview 1.0.0-preview.9
    Bedrock
    high/CVE/

    CVE-2026-11417: Command Injection in CDK NodejsFunction Local Bundling

    CVE-2026-11417Bulletin 2026-041-AWS

    AWS bulletin 2026-041-AWS covers an OS command injection issue in the aws-cdk-lib NodejsFunction local bundling pipeline.

    An actor who controls bundling properties such as externalModules, define, loader, inject, or esbuildArgs can execute arbitrary commands on the host running the CDK toolchain via injected shell metacharacters.

    Upgrade to aws-cdk-lib 2.245.0, or 2.246.0 on Windows.

    Affected
    • aws-cdk-lib < 2.245.0
    • aws-cdk-lib on Windows < 2.246.0
    Fixed In
    • aws-cdk-lib 2.245.0
    • Windows: 2.246.0
    CloudFormationLambda
    medium/CVE/

    CVE-2026-10740: Unbounded Memory Allocation in s2n-quic

    CVE-2026-10740Bulletin 2026-042-AWS

    AWS bulletin 2026-042-AWS covers a denial-of-service issue in the s2n-quic CRYPTO frame reassembler.

    Unauthenticated attackers can send crafted CRYPTO frames with high offsets to exhaust server memory: a single 1200-byte packet can trigger roughly 9.4 MB of allocation, with no valid handshake required.

    Upgrade to s2n-quic v1.82.0.

    Affected
    • s2n-quic < v1.82.0
    Fixed In
    • s2n-quic v1.82.0
    high/CVE/

    CVE-2026-12043: Heap Double-Free in aws-c-http Hits the C++ and Java SDKs

    CVE-2026-12043Bulletin 2026-043-AWS

    AWS bulletin 2026-043-AWS covers a heap double-free in aws-c-http, the HTTP client library consumed by AWS SDKs, triggered by improper handling of HTTP/2 HPACK dynamic table size updates.

    A remote actor operating a server could corrupt memory on a connecting client via a crafted sequence of HTTP/2 HEADERS frames, potentially leading to arbitrary code execution. Amazon assigns it CVSS 3.1 8.8. Affected consumers listed by AWS include the AWS SDK for C++ (1.11.41 through 1.11.814) and the AWS SDK for Java v2.

    The fix landed in aws-c-http 0.11.0: rebuild against it or pick up SDK releases that bundle it.

    Affected
    • aws-c-http 0.4.22 - 0.10.15
    • AWS SDK for C++ 1.11.41 - 1.11.814
    • AWS SDK for Java v2 (see bulletin)
    Fixed In
    • aws-c-http 0.11.0

    Key Takeaway

    1 item
    $ cat WEEKLY_SUMMARY.md

    Every bulletin this week sits in the toolchain, not the cloud control plane: the code you build and deploy with is now the attack surface. Patch the AgentCore CLI and aws-cdk-lib first, then check whether your C++ or Java builds pin a vulnerable aws-c-http. And if Klue connects to your Salesforce, revoke and reissue those tokens now.

    Filed Under
    CVEAgentCoreCDKSupply ChainOAuthIncidentSDKs2n-quic
    Previous
    Week 23 - June 1-7, 2026
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    Week 25 - June 15-21, 2026

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