What’s Vulnerable › Vulnerabilities

CVE-2020-8293

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-26 · updated 2026-06-17
• Weakness: CWE-400

Description

A missing input validation in Nextcloud Server before 20.0.2, 19.0.5, 18.0.11 allows users to store unlimited data in workflow rules causing load and potential DDoS on later interactions and usage with those rules.

Affected products

• Nextcloud Server: before 18.0.11; from 19.0.0 before 19.0.5; from 20.0.0 before 20.0.2 — fixed in 18.0.11, 19.0.5, 20.0.2

How to fix

Upgrade to a fixed version: Nextcloud Server 18.0.11, 19.0.5, 20.0.2. Check the vendor advisory for mitigations.

References

• https://hackerone.com/reports/1018146
• https://nextcloud.com/security/advisory/?id=NC-SA-2021-001
• https://hackerone.com/reports/1018146
• https://nextcloud.com/security/advisory/?id=NC-SA-2021-001

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