How to Answer Vendor Security Questionnaires About Your Secure Software Supply Chain
Enterprise security reviews are not a formality — they are a gate. If your answers are vague, your deal stalls. If your artifacts are missing, your deal dies. This guide walks you through what buyers are actually asking and what evidence you need to produce.
Buyers want to know three things: do you know what is in your software, can you prove it is not obviously exploitable, and can you show evidence rather than promises. Most questionnaires cluster into these areas:
- Do you maintain a Software Bill of Materials (SBOM)?
- What format — SPDX, CycloneDX, VEX?
- How frequently is it updated?
- What is your CVE remediation SLA for critical findings?
- What base images do you use, and are they hardened?
- Can you show evidence of attack-surface reduction in your container images?
- Do you know what actually executes in production at runtime?
- Can you provide signed build attestations?
- Are your containers aligned to CIS, STIG, or FIPS benchmarks?
When you maintain a secure software supply chain, answers to these questions become routine rather than heroic.
Lead with your SBOM export capability. The moment you can say "here is a CycloneDX SBOM generated from our production image on every build," the tone of the review shifts. If you cannot produce one on demand, that gap will surface. Fix it before the questionnaire arrives.
Quantify your CVE posture — do not just describe it. "We patch regularly" does not close deals. Buyers want current CVE counts by severity, your remediation SLA, and a scan report they can verify. Have it ready.
Separate what your container contains from what it runs. A container image can carry hundreds of packages that never execute at runtime. Buyers increasingly want evidence of runtime profiling showing what is actually active. Good software supply chain security]security practice now includes this layer, not just static scanning.
Map answers to named benchmarks. "We harden our containers" is weak. "Our containers pass CIS Level 2 and STIG checks" is actionable. Name the benchmark, reference the tool.
Build a standing artifact package and version it. Do not reassemble evidence per questionnaire. Maintain a current SBOM, CVE summary, scan date, and benchmark report. When a questionnaire arrives, you pull the latest package.
Machine-readable SPDX or CycloneDX, generated from your exact production image, automated in CI. A VEX document flagging non-reachable CVEs strengthens this further.
A snapshot of critical, high, medium, and low findings for each production image, with a scan date. Distinguish CVEs in runtime-reachable code from those in unused components.
A before/after CVE count from a credible tool, plus benchmark alignment. Most base images ship with far more than production workloads need. Show that you reduced the attack surface with hardened container images.
Static SBOMs answer what is in your image. Runtime data answers what executes. Buyers who understand container security will ask the second question. A Runtime Bill of Materials (RBOM) produced under real workloads is rare, valuable evidence.
Signed builds and verifiable attestations show that what you shipped is what you built and that the build process was controlled. Table stakes for FedRAMP; increasingly expected everywhere.
Update on every production build, not on a calendar. An SBOM more than a few weeks old is immediately suspect. Buyers ask for the generation date. Automate generation in your CI pipeline and treat the SBOM as an artifact alongside your container image.
Disclose and explain. Stating that a CVE is not reachable in your runtime profile and is scheduled for remediation next cycle is far better than a surprise finding during their own review. Show your current state and your trajectory.
Start with your base image. Most CVE exposure in containers originates there, not in application code. Switch to a hardened, minimized base, generate your SBOM from that image, run a benchmark scan, and update your artifact package. That sequence can be completed in days and produces concrete, verifiable evidence.
The vendors who close enterprise deals consistently are not necessarily the most sophisticated. They are the ones who produce evidence quickly, present it clearly, and answer follow-ups without scrambling. That capability comes from process.
If your current state is "we would have to gather that manually," the questionnaire is not your problem — the lack of process is. Build the artifact package now, automate your SBOM, profile your runtime, and align to a named benchmark. When the next review arrives, your job becomes routing, not research.