CVE intelligence and bounded remediation

CVE-2021-47970 — Macaron Notes security vulnerability

High CVSS 8.7

Macaron Notes 5.5 contains a denial of service vulnerability that allows attackers to crash the application by creating notes with excessively long character strings. Attackers can generate a payload containing 350000 repeated characters and paste it into a note field to trigger application crash and stop functionality.

Severity
High
CVSS
8.7 (4.0)
Published
2026-05-16
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-789

Affected products

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Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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