ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2021-47971

My Notes Safe 5.3 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character strings into note fields.

Published May 16, 2026 · catalog updated Jun 17, 2026 · My Notes Safe 5.3

Check if you run it

No confirmed exploitation is on record for CVE-2021-47971. EPSS is 0.28%. Act only if a listed version of My Notes Safe 5.3 is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (My Notes Safe 5.3).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.28%
Remediation
Not established
Affected products
See sources for product scope

My Notes Safe 5.3 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character strings into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to trigger an application crash.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2021-47971

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-47971. EPSS is 0.28%. Act only if a listed version of My Notes Safe 5.3 is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-789. EPSS 0.28%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 16, 2026 · NIST NVD

    Detected

    My Notes Safe 5.3 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character strings into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to trigger an application crash.

  2. Jun 17, 2026 · NIST NVD

    Updated

    My Notes Safe 5.3 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character strings into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to trigger an application crash.

Sources

  • CVE.orgVulnerability recordCVE-2021-47971

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-47971

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2021-47971

    My Notes Safe 5.3 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character strings into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.