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
- 2026-05-10
- Advisory published
- 2026-05-10
- Advisory updated
- 2026-05-10
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.
Official resources
The supplied CVE/NVD record shows a publication and modification timestamp of 2026-05-10T13:16:30.760Z. This debrief uses only the supplied corpus and the listed official/reference links.