CVE-2026-33737
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 · uneditedChamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, multiple files use simplexml_load_string() without XXE protection. With LIBXML_NOENT flag, arbitrary server files can be read. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.
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 analysisAn XML parser processes external entity references inside untrusted documents, letting an attacker read local files, reach internal systems, or exhaust resources. It's a common trap in anything that accepts XML. The fix is to disable external entities and DTD processing in the parser.
General guidance for the xml external entity (xxe) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
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< 1.11.38= 2.0.0CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
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.
dbcve · scoped1.11.38
1.11.38 (or 2.0.0-RC.3 for the 2.x branch)
- 1. Create a complete backup of the Chamilo LMS database and all application files
- 2. Place the application in maintenance mode or take it offline to prevent user activity during upgrade
- 3. Download Chamilo LMS version 1.11.38 (or 2.0.0-RC.3 if upgrading from the 2.x branch) from the official repository at https://github.com/chamilo/chamilo-lms
- 4. Replace the existing application files with the files from the fixed version, preserving any local configuration
- 5. Run any database migration scripts included in the upgrade (typically via the web installer or command-line tool)
- 6. Clear all cached files and temporary directories
- 7. Verify the application is functioning correctly and test XML parsing functionality
- 8. Remove maintenance mode and restore full access
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33737 — 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-2026-33737 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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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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