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PatchSiren cyber security CVE debrief

CVE-2021-47944 Exploit Db CVE debrief

CVE-2021-47944 is a denial-of-service issue in memono Notepad 4.2. According to the supplied record, pasting very large character buffers into note fields can crash the application on iOS devices. The issue is recorded with high severity and an availability-focused impact, but the supplied corpus does not show evidence of code execution, data theft, or KEV inclusion.

Vendor
Exploit Db
Product
Unknown
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-10
Original CVE updated
2026-07-25
Advisory published
2026-05-10
Advisory updated
2026-07-25

Who should care

Organizations or users running memono Notepad 4.2 on iOS, especially teams that rely on the app for day-to-day note taking and cannot tolerate application crashes or loss of availability.

Technical summary

The supplied description says the app can be crashed by pasting excessively long repeated-character input into note fields. NVD maps the issue to CWE-789 in the provided metadata and assigns a CVSS 4.0 vector with high availability impact. The corpus supports a crash/DoS condition, but it does not establish more severe outcomes.

Defensive priority

High for affected iOS users and maintainers because the flaw can reliably interrupt availability, though the supplied evidence points to a crash-only outcome rather than broader compromise.

Recommended defensive actions

  • Confirm whether memono Notepad 4.2 is in use on iOS devices and treat it as affected until a fixed version is verified.
  • Apply an official update or replace the app as soon as a patched version is available.
  • If you maintain the application, enforce strict input-length limits and safer handling for pasted note content.
  • Monitor crash reports and telemetry for note-field input failures to identify exposure quickly.
  • If immediate patching is not possible, reduce exposure by limiting untrusted or bulk-pasted content in the app.

Evidence notes

The supplied NVD record for CVE-2021-47944 was published and modified on 2026-05-10T13:16:30.760Z and references an Exploit-DB entry plus a VulnCheck advisory. The description states that memono Notepad 4.2 can crash on iOS when excessively long text is pasted into note fields. The supplied corpus does not include a KEV listing or any evidence of exploitation beyond the reported crash condition.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-47944 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-47944

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

  • CVE-2021-47944 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-47944

    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.