CVE-2026-45543: CWE-552: Files or Directories Accessible to External Parties in nextcloud security-advisories
Nextcloud versions from 4.3.0 up to but not including 5.2.7 contain a vulnerability where a removed collaborator retains unauthorized read access to uploaded respondent files for forms they previously had access to. This issue is limited to files associated with those specific forms. The vulnerability has been addressed and patched in version 5.2.7.
AI Analysis
Technical Summary
CVE-2026-45543 is a medium severity vulnerability in Nextcloud's security-advisories product affecting versions 4.3.0 through 5.2.6. It involves improper access control where a collaborator removed from a form retains read access to uploaded respondent files for that form. The vulnerability is categorized under CWE-552, indicating files or directories accessible to external parties. The issue has been fixed in Nextcloud version 5.2.7.
Potential Impact
An unauthorized user who was previously a collaborator on a form can continue to read uploaded respondent files even after their access was revoked. This results in unintended data exposure limited to files associated with the affected forms. There is no indication of modification or availability impact, and no known exploits in the wild.
Mitigation Recommendations
Upgrade Nextcloud to version 5.2.7 or later, where this vulnerability has been patched. No other mitigation is indicated or required.
CVE-2026-45543: CWE-552: Files or Directories Accessible to External Parties in nextcloud security-advisories
Description
Nextcloud versions from 4.3.0 up to but not including 5.2.7 contain a vulnerability where a removed collaborator retains unauthorized read access to uploaded respondent files for forms they previously had access to. This issue is limited to files associated with those specific forms. The vulnerability has been addressed and patched in version 5.2.7.
CVSS v3.1
Score 5.3medium
Affected software
pkg:github/nextcloud/formsRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-45543 is a medium severity vulnerability in Nextcloud's security-advisories product affecting versions 4.3.0 through 5.2.6. It involves improper access control where a collaborator removed from a form retains read access to uploaded respondent files for that form. The vulnerability is categorized under CWE-552, indicating files or directories accessible to external parties. The issue has been fixed in Nextcloud version 5.2.7.
Potential Impact
An unauthorized user who was previously a collaborator on a form can continue to read uploaded respondent files even after their access was revoked. This results in unintended data exposure limited to files associated with the affected forms. There is no indication of modification or availability impact, and no known exploits in the wild.
Mitigation Recommendations
Upgrade Nextcloud to version 5.2.7 or later, where this vulnerability has been patched. No other mitigation is indicated or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-12T17:48:47.879Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a1de306e29bf47b503a5595
Added to database: 06/01/2026, 19:52:38 UTC
Last enriched: 06/08/2026, 21:08:16 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 100
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