vulnerability / NVI-00002837 / Revision 3
Kimai has Server-Side Request Forgery in Invoice PDF Rendering via Markdown Image URLs
GitHub lists this reviewed advisory for kimai/kimai. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.3 MEDIUM (4.0)
security-advisories@github.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
kimai/kimai
source listed<= 2.57.0
### Summary Kimai 2.56.0 contains a server-side request forgery vulnerability in its invoice PDF preview and generation workflow. If an attacker can control Markdown content that is later rendered into an invoice PDF, such as `Customer.invoiceText`, the server-side PDF renderer will fetch remote image URLs embedded in Markdown image syntax. This allows the application server to issue outbound requests to attacker-controlled or internal targets during PDF rendering. The behavior can be used for internal network probing, server-side reachability checks, and potentially follow-on exploitation depending on deployment environment and accessible internal services. ### Details The vulnerable behavior occurs in the invoice rendering chain when user-controlled Markdown is transformed into HTML and then rendered by mPDF. - First, customer invoice text is copied into the invoice model. . Second, the default PDF invoice template renders that field through the Markdown-to-HTML filter. - Third, `md2html` enables full Markdown rendering. - Although safe mode is enabled, the tested Markdown image syntax still survives into the rendered HTML chain in a form that causes the PDF renderer to fe
kimai/kimai
source listedECOSYSTEM: introduced 0; fixed 2.58.0
### Summary Kimai 2.56.0 contains a server-side request forgery vulnerability in its invoice PDF preview and generation workflow. If an attacker can control Markdown content that is later rendered into an invoice PDF, such as `Customer.invoiceText`, the server-side PDF renderer will fetch remote image URLs embedded in Markdown image syntax. This allows the application server to issue outbound requests to attacker-controlled or internal targets during PDF rendering. The behavior can be used for internal network probing, server-side reachability checks, and potentially follow-on exploitation depending on deployment environment and accessible internal services. ### Details The vulnerable behavior occurs in the invoice rendering chain when user-controlled Markdown is transformed into HTML and then rendered by mPDF. - First, customer invoice text is copied into the invoice model. . Second, the default PDF invoice template renders that field through the Markdown-to-HTML filter. - Third, `md2html` enables full Markdown rendering. - Although safe mode is enabled, the tested Markdown image syntax still survives into the rendered HTML chain in a form that causes the PDF renderer to fe
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
- vendor patch
The original advisory lists fixed boundaries 2.58.0 for kimai/kimai. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-pj8j-p4g4-4vw8 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-pj8j-p4g4-4vw8 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-49865 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.