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SQL InjectionWeakness · CWE-89

CVE-2026-63233

CRITICAL · 9.9 CVSS v3.1 Published 2026-07-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click 3 weeks old

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 · unedited
A SQL injection and unsafe deserialisation vulnerability in Koollab LMS allowed an authenticated attacker to inject through the assessment overall answer endpoint, control data passed to unserialize(), write a webshell to a publicly accessible location, and execute arbitrary code on the server.

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 confidence

Koollab LMS contains a SQL injection vulnerability in the assessment overall answer endpoint that allows an authenticated attacker to inject SQL and control data passed to PHP's unsafe unserialize() function. This chain enables writing a webshell to a publicly accessible location and achieving remote code execution.

MitigationApply vendor patches immediately. Until then, restrict network access to the assessment endpoints, enforce strict input validation, replace unserialize() with safe alternatives like json_decode(), and use parameterized queries for all SQL operations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Koollab LMS installation and version
    Identify if your system runs Koollab LMS and determine the installed version by checking application metadata, version files, or admin panel information. Compare your version against any known version boundaries.
    Affected if You are running Koollab LMS and your version falls within an affected range (if version data becomes available).
  2. Determine if assessment module is enabled
    Check whether the assessment/quiz functionality is active in your Koollab LMS installation. This may involve reviewing enabled modules in the admin interface or configuration files.
    Affected if The assessment module is enabled and exposed to authenticated users.
  3. Verify authentication is configured for the assessment endpoint
    Inspect access controls for the 'assessment overall answer' endpoint. Determine if it requires valid authentication or if it can be accessed anonymously.
    Affected if The endpoint accepts requests from authenticated users (including low-privilege accounts) and processes their input.
  4. Search for unsafe unserialize() calls in assessment code
    Locate and inspect PHP files handling assessment data, specifically looking for unserialize() function calls that process user-controlled data without proper validation. Search the codebase for patterns like 'unserialize($_POST', 'unserialize($_GET', or 'unserialize($data'.
    Affected if Code contains unserialize() calls that process data controllable by users without sanitization.
  5. Check for direct SQL queries without prepared statements
    Review database query code in assessment-related PHP files. Look for SQL queries constructed through string concatenation or interpolation rather than parameterized queries or prepared statements.
    Affected if SQL queries in assessment functionality use string concatenation with user input rather than bound parameters.
  6. Inspect publicly writable directories for webshells
    Examine web-accessible directories (such as public upload folders, static asset directories, or web root subdirectories) for unexpected PHP files that may be webshells. Compare against known-good file lists or deployment baselines.
    Affected if Unexpected PHP scripts exist in publicly accessible locations, indicating potential prior exploitation.

You are likely affected if running Koollab LMS with the assessment module enabled, the endpoint is accessible to authenticated users, and your codebase contains unsafe unserialize() calls or direct SQL concatenation in assessment-related code paths.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor patches immediately. Until then, restrict network access to the assessment endpoints, enforce strict input validation, replace unserialize() with safe alternatives like json_decode(), and use parameterized queries for all SQL operations.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-63233 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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