CVE-2021-47971 My Notes Safe 5.3 Denial of Service via Buffer Overflow
Attackers can crash My Notes Safe by pasting excessively long character strings into note fields, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-47971?
CVE-2021-47971 is a high-severity denial of service vulnerability in my-notes-safe My Notes Safe, published on 16 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-789
Which versions are affected by CVE-2021-47971?
How do I fix CVE-2021-47971?
No fix has been published for CVE-2021-47971 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-47971 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47971 exists.
Sources
Also known as GHSA-w4w9-25xj-f9j4.