PT-2026-45475 · Nextcloud · Nextcloud

34Selen · CVE-2026-45264 · Published 2026-06-01 · Updated 2026-06-01

Positive Technologies (AI Summary)

CVSS v3.1

4.3

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Name of the Vulnerable Software and Affected Versions Nextcloud versions 17.0.0 through 17.0.14 Nextcloud versions 18.0.0 through 18.1.11 Nextcloud versions 19.0.0 through 19.1.15 Nextcloud versions 20.0.0 through 20.1.10 Nextcloud versions 21.0.0 through 21.0.3

Description An Access Control List (ACL) permission bypass exists in team folders. A user granted READ and CREATE permissions, but lacking UPDATE permissions, can unauthorizedly rename files within the team folder.

Recommendations Update to version 17.0.15 Update to version 18.1.12 Update to version 19.1.16 Update to version 20.1.11 Update to version 21.0.4

Exploit

Fix

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

CVE-2026-45264

GHSA-WX2X-822R-RVMF

Affected Products

Nextcloud

References · 7

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45264.json · Exploit
• https://osv.dev/vulnerability/CVE-2026-45264 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-45264 · Security Note
• https://github.com/nextcloud/groupfolders/pull/4361 · Note
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wx2x-822r-rvmf · Note
• https://t.me/CVEtracker/55511 · Telegram Post
• https://hackerone.com/reports/3540673 · Note