CVE-2026-28228
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 · uneditedOpenOlat is an open source web-based e-learning platform for teaching, learning, assessment and communication. Prior to versions 19.1.31, 20.1.18, and 20.2.5, an authenticated user with the Author role can inject Velocity directives into a reminder email template. When the reminder is processed (either triggered manually or via the daily cron job), the injected directives are evaluated server-side. By chaining Velocity's #set directive with Java reflection, an attacker can instantiate arbitrary Java classes such as java.lang.ProcessBuilder and execute operating system commands with the privileges of the Tomcat process (typically root in containerized deployments). This issue has been patched in versions 19.1.31, 20.1.18, and 20.2.5.
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 confidenceOpenOlat versions prior to 19.1.31, 20.1.18, and 20.2.5 suffer from a Server-Side Template Injection (SSTI) vulnerability. Authenticated users with Author role can inject malicious Velocity directives into reminder email templates. When processed (manually or via cron), these directives are evaluated server-side, enabling arbitrary Java class instantiation and OS command execution via Java reflection with Tomcat process privileges.
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< 19.1.31>= 20.0.0, < 20.1.18>= 20.2.0, < 20.2.5CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed OpenOlat versionCheck the OpenOlat version file (typically in /opt/openolat/VERSION or within the application WAR bundle metadata), or access the administration panel and navigate to Administration > System > Info to view the installed version number.Affected if The installed version is less than 19.1.31, OR between 20.0.0 and 20.1.17 inclusive, OR between 20.2.0 and 20.2.4 inclusive.
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Verify if Author role exists and is assignableIn the OpenOlat administration interface, navigate to Administration > Roles & Permissions > Role management. Check if the Author role is present and whether it can be assigned to users.Affected if The Author role exists and is active, meaning users can be granted template editing capabilities.
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Confirm reminder email templates are presentLocate the reminder email template configuration files in the OpenOlat installation directory (typically under /opt/openolat/conf/mail/ or within the webapp resources), or access the template editor via the Author role interface if available.Affected if Reminder email templates exist in the system and can be accessed for modification.
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Check for existing cron job configurationsInspect the system cron jobs (crontab -l) and OpenOlat internal scheduler configurations for any entries that process reminder emails or execute template rendering jobs.Affected if Cron jobs or scheduler tasks exist that trigger reminder email processing, enabling template evaluation.
A user is affected if their OpenOlat version falls within the vulnerable ranges AND the Author role is assignable with access to modify reminder email templates, AND reminder processing is triggered via cron or manual action.
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.
dbcve · scoped19.1.3120.1.1820.2.5
Upgrade to OpenOlat versions 19.1.31, 20.1.18, or 20.2.5 which contain the patch. If immediate patching is not possible, disable or restrict the Author role and disable reminder email processing until the upgrade can be applied.
Upgrade to version 20.2.5 (or 19.1.31/20.1.18 depending on current branch)
- 1. Identify the currently installed OpenOlat version in the deployment environment
- 2. Determine the appropriate upgrade path based on current version (19.1.x -> 19.1.31, 20.0.x or 20.1.x -> 20.1.18, or 20.2.x -> 20.2.5)
- 3. Review the official OpenOlat upgrade documentation for your version branch
- 4. Create a complete backup of the database and application files before upgrading
- 5. Stop the Tomcat service running OpenOlat
- 6. Deploy the target fixed version (19.1.31, 20.1.18, or 20.2.5) following standard upgrade procedures
- 7. Run any database migration scripts included in the upgrade
- 8. Restart the Tomcat service
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-28228 — 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-2026-28228 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