CVE-2026-45267: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in nextcloud security-advisories
Nextcloud versions prior to 5. 2. 6 contain a vulnerability where a missing permissions check allows users to read form submissions of other users without authorization. This issue exposes sensitive information to unauthorized actors. The vulnerability has been addressed and patched in version 5. 2. 6.
AI Analysis
Technical Summary
CVE-2026-45267 is a vulnerability in Nextcloud's security-advisories product affecting versions before 5.2.6. It involves a missing permissions check that permits unauthorized users with limited privileges to access form submissions belonging to other users. This results in exposure of sensitive information (CWE-200) due to improper access control (CWE-862). The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The issue was publicly disclosed in June 2026 and fixed in Nextcloud version 5.2.6.
Potential Impact
Unauthorized users with limited privileges can read sensitive form submission data of other users, leading to confidentiality breaches. There is no impact on integrity or availability reported. No known exploits in the wild have been identified.
Mitigation Recommendations
Upgrade Nextcloud to version 5.2.6 or later where this vulnerability has been patched. Since the vendor advisory confirms the issue is fixed in 5.2.6, applying this official fix fully mitigates the risk.
CVE-2026-45267: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in nextcloud security-advisories
Description
Nextcloud versions prior to 5. 2. 6 contain a vulnerability where a missing permissions check allows users to read form submissions of other users without authorization. This issue exposes sensitive information to unauthorized actors. The vulnerability has been addressed and patched in version 5. 2. 6.
CVSS v3.1
Score 6.5medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-45267 is a vulnerability in Nextcloud's security-advisories product affecting versions before 5.2.6. It involves a missing permissions check that permits unauthorized users with limited privileges to access form submissions belonging to other users. This results in exposure of sensitive information (CWE-200) due to improper access control (CWE-862). The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The issue was publicly disclosed in June 2026 and fixed in Nextcloud version 5.2.6.
Potential Impact
Unauthorized users with limited privileges can read sensitive form submission data of other users, leading to confidentiality breaches. There is no impact on integrity or availability reported. No known exploits in the wild have been identified.
Mitigation Recommendations
Upgrade Nextcloud to version 5.2.6 or later where this vulnerability has been patched. Since the vendor advisory confirms the issue is fixed in 5.2.6, applying this official fix fully mitigates the risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-11T18:41:13.156Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a1dbba7e29bf47b501c580f
Added to database: 6/1/2026, 5:04:39 PM
Last enriched: 6/1/2026, 5:20:00 PM
Last updated: 6/1/2026, 7:34:39 PM
Views: 15
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