# Safe Codex Prompt: CVE-2026-64269

Prepare a defensive remediation plan for CVE-2026-64269.

Use only the public-safe context below unless the user separately provides repo context.

Source summary: NVD: In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg When the server answers an RTRS READ, rdma_write_sg() builds the source scatter/gather entry for the IB_WR_RDMA_WRITE... NVD: Its length is taken directly from the wire descriptor: plist->length = le32_to_cpu(id->rd_msg->desc[0].len); rd_msg points into the chunk buffer that the remote peer filled via RDMA-WRITE-WITH-IMM (rtrs_srv_rdma_done() -> process_io_req() -> process_read())... NVD: The source address is the fixed chunk start (dma_addr[msg_id]) and the source lkey is the PD-wide local_dma_lkey, which is not tied to the chunk's MR mapping, so the
Affected vendor/product: unknown / Kernel
Risk context: {'severity': 'CRITICAL', 'cvss_score': 9.1, 'cvss_label': 'CRITICAL', 'epss_percentile': 0.48786, 'kev_status': 'not_listed', 'risk_flags': ['CVSS CRITICAL', 'official reference present']}
Remediation context: {'recommended_route': 'vendor_patch_or_mitigation', 'reference_status': 'official_reference_present', 'patch_status': 'requires_confirmation', 'fixed_versions': [], 'mitigation_notes': ['Remediation reference present; patch status requires confirmation in the linked advisory.', 'Patch status requires confirmation from the linked advisory or official source.']}

Human checklist:
- Confirm whether the listed product or package is present.
- Confirm affected version.
- Review vendor advisory or official source.
- Confirm patch, fixed version, mitigation, workaround, or monitor-only decision.
- Confirm exposure.
- Document remediation status.

Allowed actions:
- summarize vendor guidance
- prepare a defensive remediation plan
- identify affected dependencies only when repo context is separately provided by the user
- suggest tests and validation steps
- document human verification questions

Disallowed actions:
- generate offensive code
- provide payloads
- scan external targets
- change production systems
- merge or deploy changes
- create GitHub issues or pull requests without explicit separate approval

Acceptance criteria:
- Affected product or dependency presence is confirmed by a human.
- Affected version is confirmed or marked not applicable.
- Official advisory or source reference is reviewed.
- Patch, fixed version, mitigation, workaround, or monitor-only decision is documented.
- Validation steps are proposed without external scanning or production mutation.

You may prepare a defensive remediation plan.
You may summarize vendor guidance.
You may identify affected dependencies only if repo context is separately provided by the user.
You may suggest tests and validation steps.
You must not generate offensive code.
You must not provide payloads.
You must not scan external targets.
You must not change production systems.
You must not merge or deploy.
Human approval is required.