CVE-2020-26260
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedBookStack is a platform for storing and organising information and documentation. In BookStack before version 0.30.5, a user with permissions to edit a page could set certain image URL's to manipulate functionality in the exporting system, which would allow them to make server side requests and/or have access to a wider scope of files within the BookStack file storage locations. The issue was addressed in BookStack v0.30.5. As a workaround, page edit permissions could be limited to only those that are trusted until you can upgrade.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn BookStack before version 0.30.5, a user with page edit permissions could manipulate image URLs to exploit the export system, enabling server-side request forgery (SSRF) and path traversal attacks. This allowed attackers to make arbitrary server requests and access files outside the intended BookStack storage locations.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 0.30.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed BookStack versionLocate the version number in the application footer, in the .env file (APP_VERSION setting), or by running 'php artisan --version' in the BookStack directoryAffected if The version is below 0.30.5 (e.g., 0.30.0, 0.29.x, etc.)
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Verify page edit permission existsIn BookStack admin panel, go to Roles and Permissions section to review which roles have the 'page edit' permission enabledAffected if Any role other than Admin has the 'page edit' permission granted to untrusted users
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Confirm export functionality is accessibleCheck if the page export feature is enabled in the system by navigating to a page and looking for the 'Export' option in the page actions menuAffected if The export feature is available and users with page edit permissions can access it
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Review image URL handling in exportsInspect the /exports/html endpoint or related export code to verify if user-supplied image URLs are used directly without sanitizationAffected if The system allows custom image URLs in page content that get processed during export without validation
A defender is affected if their BookStack version is below 0.30.5 AND untrusted users have page edit permissions with access to the export system.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data0.30.5
Upgrade to BookStack v0.30.5 or later. Alternatively, restrict page edit permissions to trusted users until the upgrade can be completed.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-26260 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-26260 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data