Fulgur: Unbounded page slicing from attacker-controlled CSS height causes denial of service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.
Summary
`fulgur` converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. In versions prior to 0.19.0, a body-direct child whose CSS-resolved height greatly exceeds the page height was sliced into one fragment per page with no upper bound. This is fixed in version 0.19.0. A `MAX_PAGES` cap bounds the slice loop — halting it even for a `+inf` height — and non-finite layout heights are sanitized so they can no longer drive the loop. As a workaround, validate or constrain untrusted CSS (in particular `height` / `vh` on body-level elements) before passing HTML to fulgur.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| fulgur-rs | fulgur | before 0.19.0 | 0.19.0 | Patch available | CNA |
| — | fulgur (crates.io) | before 0.26.0 | 0.26.0 | Patch available | GHSA-4rf6-qx84-q9fv |
- fulgur Vendorfulgur-rs Affected before 0.19.0 Fixed in 0.19.0 Patch available CNA
- fulgur (crates.io) Vendor— Affected before 0.26.0 Fixed in 0.26.0 Patch available GHSA-4rf6-qx84-q9fv
Remediation
- Fix · CNA fulgur (fulgur-rs) Fixed in 0.19.0
- Fix · GHSA-4rf6-qx84-q9fv fulgur (crates.io) Fixed in 0.26.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-68537
- 2026-10-03 Alias added: GHSA-4rf6-qx84-q9fv
References
Other 6
- https://github.com/fulgur-rs/fulgur/security/advisories/GHSA-4rf6-qx84-q9fv
- https://github.com/fulgur-rs/fulgur/pull/501
- https://rustsec.org/advisories/RUSTSEC-2026-0200.html
- https://github.com/fulgur-rs/fulgur/pull/575
- https://github.com/fulgur-rs/fulgur
- https://rustsec.org/advisories/RUSTSEC-2026-0201.html
More fulgur-rs vulnerabilities
- TI-2026-48287 Fulgur: Unbounded page slicing from attacker-controlled CSS height causes denial of service CVSS 3.1HIGH 7.5
Sources
- CVE-2026-68537 · CVE Program
- CVE-2026-68537 · NVD
- FIRST EPSS
- GHSA-4rf6-qx84-q9fv · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences