PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-4931 Marginal CVE debrief

CVE-2026-4931 is a medium-severity smart contract flaw associated with Marginal v1. The issue is described as an unsafe downcast / incorrect numeric conversion that can let an attacker settle a large debt position for a negligible asset cost. NVD lists the record as awaiting analysis, so the public picture is still limited, but the reported impact is strongly integrity-focused and relevant to on-chain accounting and settlement logic.

Vendor
Marginal
Product
Marginal Smart Contract
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-07
Original CVE updated
2026-04-08
Advisory published
2026-04-07
Advisory updated
2026-04-08

Who should care

Teams operating, integrating, or auditing Marginal v1 or Marginal Protocol smart contracts should pay attention, especially protocol maintainers, DeFi developers, security reviewers, and any users or services that rely on debt settlement logic.

Technical summary

The available evidence points to CWE-681 (incorrect conversion between numeric types). In the described failure mode, an unsafe downcast can truncate or otherwise distort numeric values used in settlement calculations. If a contract uses the converted value to determine how much asset is required to close a debt position, the result can be a severe undercharge and an integrity break. The supplied CVSS vector (AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N) indicates network-reachable impact with high attack complexity and no required privileges or user interaction.

Defensive priority

Medium

Recommended defensive actions

  • Review all numeric conversions in Marginal v1 settlement and accounting code for unsafe downcasts or truncation.
  • Add explicit bounds checks before any type conversion that can reduce numeric range.
  • Prefer safe casting helpers or conversion libraries where available, and fail closed on overflow or truncation risk.
  • Re-test debt settlement, liquidation, and fee-calculation paths with boundary-value inputs.
  • Have an independent security review focus on CWE-681 patterns and related SCWE-041 guidance.
  • Monitor vendor and NVD updates for analysis clarifications and any affected-version details.

Evidence notes

This debrief uses only the supplied corpus. The core evidence is the CVE description provided in the prompt, the NVD metadata showing CVSS 3.1 vector AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N, the weakness mapping to CWE-681, and the reference set pointing to Marginal Protocol documentation and OWASP SCWE-041. NVD vulnerability status is listed as Awaiting Analysis, so affected versions and exploitability details should be treated as incomplete unless confirmed by later vendor or database updates.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-4931 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-4931

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-4931 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-4931

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.