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PatchSiren cyber security CVE debrief

CVE-2021-47969 Exploit Db CVE debrief

CVE-2021-47969 is a high-severity denial-of-service issue in Color Notes 1.4. The supplied description says an attacker can crash the application by pasting excessively long character strings into note fields; the example payload is 350,000 repeated characters pasted twice into a new note, which can cause the app to stop responding. The supplied NVD metadata classifies the issue as network-reachable, low-complexity, no-privileges, no-user-interaction, and availability-impacting only. The supplied timeline records the CVE as published and modified on 2026-05-16T16:16:22.170Z.

Vendor
Exploit Db
Product
Unknown
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-16
Original CVE updated
2026-05-18
Advisory published
2026-05-16
Advisory updated
2026-05-18

Who should care

Administrators and users running Color Notes 1.4, especially where untrusted text can be pasted into notes or where application availability is important.

Technical summary

The vulnerability is described as a denial of service caused by oversized pasted input in note fields. The supplied weakness mapping is CWE-789, and the CVSS v4 vector indicates AV:N/AC:L/AT:N/PR:N/UI:N with high availability impact and no confidentiality or integrity impact. In practical terms, the application can be forced into a non-responsive state through crafted input length rather than authentication or complex interaction.

Defensive priority

High. Because the supplied vector shows no privileges and no user interaction are required, and the impact is application availability, organizations should treat this as a priority if Color Notes 1.4 is present on systems that must remain responsive.

Recommended defensive actions

  • Identify any systems running Color Notes 1.4 and treat them as exposed to availability risk until mitigated.
  • Check for and deploy any vendor-issued update, replacement, or supported remediation for Color Notes 1.4.
  • If immediate patching is not available, limit use of the application to trusted users and restrict untrusted pasted content where possible.
  • Monitor affected hosts for application hangs, crashes, or repeated stop-responding events associated with note creation or paste activity.
  • Track the official CVE/NVD record and the disclosed references for any updated remediation guidance.

Evidence notes

This debrief is based only on the supplied corpus: the NVD CVE record, the CVSS v4 metadata, the CWE mapping, and the provided disclosure references. The corpus cites https://www.exploit-db.com/exploits/49952 and https://www.vulncheck.com/advisories/color-notes-denial-of-service-via-long-character-string as disclosure sources, and the official CVE/NVD record links are included below. The supplied record shows a published/modified timestamp of 2026-05-16T16:16:22.170Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-47969 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-47969

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

  • CVE-2021-47969 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-47969

    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.