Summary
DSpace: Path Traversal is possible through LDN message generation
Full technical description
Overview
A path traversal vulnerability is possible via the COAR Notify / LDN service in DSpace. This vulnerability impacts DSpace versions 8.0 <= 8.3, 9.0 <= 9.2. The attacker MUST already have DSpace administrator credentials in order to perform the attack.
When reading a file input stream of an "inbound pattern" / "template", used to generate an LDN message, the LDN class does not check for path traversal or restrict the templates to a known base path. This could allow an untrusted file from elsewhere in the file system (e.g. an export log, a bitstream path, a temporary file) to be read and interpreted as an Apache Velocity template.
Expected behaviour : Only the trusted templates kept in $dspace.dir/config/ldn should be allowed or used by LDN.
Apply the patch to a DSpace
If at all possible, DSpace recommends disabling LDN (see below) or upgrading the user's DSpace site based on the upgrade instructions. However, if users are unable to do so, they can manually apply the above patches to their DSpace backend as follows:
- Download the appropriate patch file to the machine where DSpace backend is running
- From the
[dspace-src]folder, apply the patch, e.g.git apply [name-of-file].patch - Now, update the DSpace site (based loosely on the Upgrade instructions). This generally involves three steps:
- Rebuild DSpace, e.g.
mvn -U clean package(This will recompile all DSpace backend code) - Redeploy DSpace, e.g.
ant update(This will copy all newly built code to their installation directory). Depending on their setup they also may need to copy the updated "server" webapp over to their Tomcat webapps folder. - Restart Tomcat (or runnable JAR)
- Rebuild DSpace, e.g.
Workarounds
- In
dspace.cfgorlocal.cfg, disable LDN (setldn.enabled=false) if it is not crucial to the operation of the repository. (NOTE: LDN is disabled by default, so many DSpace sites may not use this feature) - Once users have patched their site or upgraded, they may safely enable LDN again.
Credits
Discovered & reported by Pablo Picurelli Ortiz (@superpegaso2703), cybersecurity student at Universidad Rey Juan Carlos.
Code fix developed by Kim Shepherd (@kshepherd) of The Library Code
Impact
On its own this seems a fairly low-impact problem: only DSpace Administrators can set LDN template names in services, and you typically need more access to manipulate files on the server.
However, this vulnerability was included as part of an attack chain that demonstrated the ability of a DSpace Administrator to put the malicious Velocity payload in a predictable place (e.g. temporary log file from a running process) and then have that file referenced as the template name in a new service.
This means it is possible (non-trivial, but proven) for an attacker with DSpace administrator credentials to either disclose information via a specially crafted Velocity template, or exploit another weakness in the DSpace Velocity implementation by executing arbitrary java code.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-49833 has a CVSS score of 5.5 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (8.4, 9.3, 10.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The fix is included in DSpace 8.4, 9.3 and 10.0. Please upgrade to one of these versions or disable LDN (see below)
If users cannot upgrade immediately, it is possible to manually patch their DSpace backend. (No changes are necessary to the frontend.) A pull request exists which can be used to patch systems running DSpace 8.x or 9.x.
- Pull request for 9.x: https://github.com/DSpace/DSpace/pull/12552 (Downloadable patch file)
- This 9.x patch file also resolves a similar path traversal vulnerability in the Curation Task reporter
- Pull request for 8.x: https://github.com/DSpace/DSpace/pull/12540 (Downloadable patch file)
- This 8.x patch file also resolves a similar path traversal vulnerability in the Curation Task reporter
Frequently Asked Questions
- What is CVE-2026-49833? CVE-2026-49833 is a medium-severity path traversal vulnerability in org.dspace:dspace-api (maven), affecting versions >= 8.0-rc1, <= 8.3. It is fixed in 8.4, 9.3, 10.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2026-49833? CVE-2026-49833 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.dspace:dspace-api are affected by CVE-2026-49833? org.dspace:dspace-api (maven) versions >= 8.0-rc1, <= 8.3 is affected.
- Is there a fix for CVE-2026-49833? Yes. CVE-2026-49833 is fixed in 8.4, 9.3, 10.0. Upgrade to this version or later.
- Is CVE-2026-49833 exploitable, and should I be worried? Whether CVE-2026-49833 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-49833 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-49833?
- Upgrade
org.dspace:dspace-apito 8.4 or later - Upgrade
org.dspace:dspace-apito 9.3 or later - Upgrade
org.dspace:dspace-apito 10.0 or later
- Upgrade