CVE-2026-82982: CWE-840 Business Logic Errors in Nextcloud Approval
The Approval app's approve/reject endpoint is meant to require the file's current etag as a freshness check, preventing an approver from approving or rejecting a file whose contents changed after they reviewed it. The backend only enforced this check when the etag parameter was present and non-empty in the request. An attacker able to intercept and modify the approval request could omit the etag field entirely, bypassing the freshness check and approving or rejecting a file version they never reviewed.
AI Analysis
Technical Summary
The Nextcloud Approval app's approve/reject endpoint is designed to require the file's current etag as a freshness check to prevent approving or rejecting files whose contents have changed since review. However, the backend only enforces this check if the etag parameter is included and non-empty in the request. This allows an attacker who can intercept and modify approval requests to omit the etag field entirely, bypassing the freshness check and approving or rejecting a file version without proper review. This is a business logic error categorized under CWE-840.
Potential Impact
The vulnerability allows an attacker with the capability to intercept and modify approval requests to bypass the freshness check and approve or reject file versions they have not reviewed. This could lead to unauthorized approval or rejection of file changes, impacting the integrity of the approval process. The CVSS score is 4.3 (medium severity), indicating limited impact on confidentiality and availability but some impact on integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should be cautious of potential interception and modification of approval requests. No official fix or patch links are currently provided.
CVE-2026-82982: CWE-840 Business Logic Errors in Nextcloud Approval
Description
The Approval app's approve/reject endpoint is meant to require the file's current etag as a freshness check, preventing an approver from approving or rejecting a file whose contents changed after they reviewed it. The backend only enforced this check when the etag parameter was present and non-empty in the request. An attacker able to intercept and modify the approval request could omit the etag field entirely, bypassing the freshness check and approving or rejecting a file version they never reviewed.
CVSS v3.0
Score 4.3medium
Affected software
Nextcloud
Approval
pkg:github/nextcloud/approvalRun 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
The Nextcloud Approval app's approve/reject endpoint is designed to require the file's current etag as a freshness check to prevent approving or rejecting files whose contents have changed since review. However, the backend only enforces this check if the etag parameter is included and non-empty in the request. This allows an attacker who can intercept and modify approval requests to omit the etag field entirely, bypassing the freshness check and approving or rejecting a file version without proper review. This is a business logic error categorized under CWE-840.
Potential Impact
The vulnerability allows an attacker with the capability to intercept and modify approval requests to bypass the freshness check and approve or reject file versions they have not reviewed. This could lead to unauthorized approval or rejection of file changes, impacting the integrity of the approval process. The CVSS score is 4.3 (medium severity), indicating limited impact on confidentiality and availability but some impact on integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should be cautious of potential interception and modification of approval requests. No official fix or patch links are currently provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- hackerone
- Date Reserved
- 2026-08-31T15:00:00.543Z
- Cvss Version
- 3.0
- State
- PUBLISHED
Threat ID: 6aad953c55bf5e2cf577b92d
Added to database: 09/18/2026, 19:47:08 UTC
Last enriched: 09/18/2026, 20:02:09 UTC
Last updated: 09/19/2026, 03:23:19 UTC
Views: 7
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