vulnerability / NVI-00014201 / Revision 1
Fulgur: Non-painting replaced elements amplify to thousands of blank PDF pages (denial of service)
GitHub lists this reviewed advisory for fulgur. 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.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
fulgur
source listed< 0.26.0
`fulgur` converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. In versions prior to 0.26.0, a childless box that resolves to a pathologically tall height was amplified into thousands of blank PDF pages, even when it produces no visible output. The childless-collapse defense that would normally collapse such a box was gated by a tag-only "replaced content" check, so any **non-painting replaced element** bypassed it, including: - an unresolved `src` (the common offline-first case), - a `visibility:hidden` image, - an undecodable image format, and - an empty ``. A trailing-sibling variant of the same gap was also open. A few bytes of HTML therefore amplified into roughly `MAX_PAGES` (10,000) blank pages; the renderer allocates and runs a per-page loop over them, producing CPU and memory exhaustion. An attacker able to submit HTML to a fulgur-based conversion service can trigger this with a trivially small payload, denying service to the host and any co-tenants. ## Patches Fixed in **0.26.0** (PR #575). The tag-only gate was removed so that any pathologically tall childless box collapses regardless of whether it is a replace
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. GitHub Advisory Database
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.
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-4rf6-qx84-q9fv ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.