What’s Vulnerable › Vulnerabilities

CVE-2026-45159: Nextcloud: Files drop share links for end-to-end encrypted folders allowed to drop files into other folders of the share owner

• Severity: low (CVSS 3.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-01 · updated 2026-07-22
• Weakness: CWE-639

Description

Nextcloud is an open source content collaboration platform. From versions 1.15.0 to before 1.15.4, 1.16.0 to before 1.16.3, 1.17.0 to before 1.17.1, and 1.18.0 to before 1.18.1, a malicious user with access to an end-to-end encrypted files drop link was able to also drop files into other end-to-end encrypted folders of the share owner. Reading and modifying of other files was not possible. This issue has been patched in versions 1.15.4, 1.16.3, 1.17.1, 1.18.1, and 2.0.0-rc.7.

Affected products

• nextcloud security-advisories: from 1.15.0, < 1.15.4; from 1.16.0, < 1.16.3; from 1.17.0, < 1.17.1; from 1.18.0, < 1.18.1

References

• https://github.com/nextcloud/end_to_end_encryption/pull/1395
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-p3qw-7gwx-wg24
• https://hackerone.com/reports/3304830

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