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  <id>https://vulnerability.circl.lu/sightings/feed</id>
  <title>Most recent sightings.</title>
  <updated>2026-10-02T16:34:27.801886+00:00</updated>
  <author>
    <name>Vulnerability-Lookup</name>
    <email>info@circl.lu</email>
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  <link href="https://vulnerability.circl.lu" rel="alternate"/>
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  <subtitle>Contains only the most 10 recent sightings.</subtitle>
  <entry>
    <id>https://vulnerability.circl.lu/sighting/cb7ed765-79e1-47ad-88da-60855f3bd378/export</id>
    <title>cb7ed765-79e1-47ad-88da-60855f3bd378</title>
    <updated>2026-10-02T16:34:27.827488+00:00</updated>
    <author>
      <name>Automation user</name>
      <uri>https://cve.circl.lu/user/automation</uri>
    </author>
    <content>{"uuid": "cb7ed765-79e1-47ad-88da-60855f3bd378", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-77633", "type": "seen", "source": "https://gist.github.com/alon710/0f4409fbe4cfa22658c44aa73c2a9873", "content": "# CVE-2026-77633: CVE-2026-77633: Storage-quota Time-of-Check to Time-of-Use (TOCTOU) Race Condition in Cloudreve\n\n&amp;gt; **CVSS Score:** 7.1\n&amp;gt; **Published:** 2026-09-22\n&amp;gt; **Full Report:** https://cvereports.com/reports/CVE-2026-77633\n\n## Summary\nCloudreve before version 4.18.0 contains a Time-of-Check to Time-of-Use (TOCTOU) race condition in its storage-quota verification logic. Authenticated attackers with basic write access can trigger multiple parallel upload sessions to bypass their storage limits, leading to host disk space exhaustion and Denial of Service.\n\n## TL;DR\nA TOCTOU race condition in Cloudreve allows authenticated users to bypass their storage quota limits via concurrent upload sessions, causing host disk exhaustion.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-367 / CWE-770\n- **Attack Vector**: Network (AV:N)\n- **CVSS v3.1**: 7.1 (High)\n- **Exploit Status**: PoC / Conceptual\n- **KEV Status**: Not Listed\n- **Impact**: Denial of Service (DoS) via Disk Exhaustion\n\n## Affected Systems\n\n- Cloudreve\n- **Cloudreve**: &amp;lt; 4.18.0 (Fixed in: `4.18.0`)\n\n## Mitigation\n\n- Upgrade to Cloudreve version 4.18.0 or later.\n- Implement rate limiting at the reverse proxy level on upload endpoints.\n- Configure cloud storage policies (S3, B2, etc.) to isolate storage consumption.\n\n**Remediation Steps:**\n1. Stop the Cloudreve service.\n2. Download the Cloudreve v4.18.0 binary or build from source.\n3. Update your service configuration and restart the application.\n4. Configure rate limits in Nginx/Apache for POST requests targeting '/api/v3/file/upload'.\n\n## References\n\n- [NVD - CVE-2026-77633](https://nvd.nist.gov/vuln/detail/CVE-2026-77633)\n- [GitHub Security Advisory GHSA-xj3h-wwxq-gfcj](https://github.com/cloudreve/cloudreve/security/advisories/GHSA-xj3h-wwxq-gfcj)\n- [Cloudreve v4.18.0 Release Notes](https://github.com/cloudreve/cloudreve/releases/tag/4.18.0)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/CVE-2026-77633) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-09-23T05:32:15.168308Z"}</content>
    <link href="https://vulnerability.circl.lu/sighting/cb7ed765-79e1-47ad-88da-60855f3bd378/export"/>
    <published>2026-09-23T05:32:15.168308+00:00</published>
  </entry>
  <entry>
    <id>https://vulnerability.circl.lu/sighting/743b1564-015b-4525-8b02-ba78b398ac95/export</id>
    <title>743b1564-015b-4525-8b02-ba78b398ac95</title>
    <updated>2026-10-02T16:34:27.830546+00:00</updated>
    <author>
      <name>Automation user</name>
      <uri>https://cve.circl.lu/user/automation</uri>
    </author>
    <content>{"uuid": "743b1564-015b-4525-8b02-ba78b398ac95", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-77633", "type": "seen", "source": "https://bsky.app/profile/standup.thecompound.tech/post/3mw5g5j7g3q24", "content": "Cloudreve v4 has CVE-2026-77633, a race in PrepareUpload that lets authenticated users bypass storage quotas and trigger storage-based denial of service. #software", "creation_timestamp": "2026-09-22T23:50:12.163945Z"}</content>
    <link href="https://vulnerability.circl.lu/sighting/743b1564-015b-4525-8b02-ba78b398ac95/export"/>
    <published>2026-09-22T23:50:12.163945+00:00</published>
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