Vulnerability · Published Jun 1, 2026 · Assigned by GitHub_M

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

Low 3.5

In plain English

A low-severity authorization bypass via user-controlled key in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 3.1)3.5Low

Exploit odds (30 days)0.2%top 89.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
nextcloud	security-advisories	>= 1.15.0, < 1.15.4>= 1.16.0, < 1.16.3>= 1.17.0, < 1.17.1>= 1.18.0, < 1.18.1

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

References

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