# CVE-2026-68540: fulgur denial of service in absolutely-positioned pseudo-element layout

Source: https://junglewise.ai/threats/cve-2026-68540-fulgur-converts-untrusted-html-css-into-pdf-commonly-on-a-server  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-11. Updated: 2026-11-11  
License: CC BY 4.0 with a link back

CVE-2026-68540 · Severity: high · CVSS 7.5 · Published 2026-11-11

fulgur is a library that converts untrusted HTML and CSS documents into PDFs, typically running on servers that process user-supplied input from multiple tenants. A flaw in how the library processes the layout of absolutely-positioned pseudo-elements (like ::before and ::after) causes quadratic reprocessing of style information, allowing an attacker to craft malicious documents that consume excessive CPU and cause service denial.

Technologies: [Fulgur-Rs Fulgur](https://junglewise.ai/threats/technologies/fulgur-rs-fulgur). Vendors: [Fulgur-Rs](https://junglewise.ai/threats/vendors/fulgur-rs).

## Quick answers

**Is CVE-2026-68540 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-68540 being exploited in the wild.

**How severe is CVE-2026-68540?** High severity, with a CVSS score of 7.5, published 11 November 2026.

**Which products and versions are affected?** Fulgur-Rs Fulgur 0.6.0 to before 0.33.0.

**Is there a fix for CVE-2026-68540?** Yes: fixed in 0.33.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-68540 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-68540?** Check whether you run Fulgur-Rs Fulgur at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.33.0

## Technical details

The vulnerability exists in the `cb_padding_box` function within the positioned.rs module, which was unnecessarily calling `extract_block_style()` to obtain border widths during containing-block resolution for absolutely-positioned pseudo-elements. This full style extraction triggered cloning and iteration of `box-shadow` lists as a side effect, and the containing-block resolution walk multiplied this processing across ancestors for each affected pseudo-element. An attacker can provide a document with many absolutely-positioned ::before/::after pseudo-elements whose ancestors have complex box-shadow properties, causing quadratic computational complexity and denial of service.

## Affected products

- fulgur-rs fulgur 0.6.0 to before 0.33.0

## Timeline

- 2026-11-11: disclosed

## References

- [https://github.com/fulgur-rs/fulgur/commit/8fabbca271313c56ef48f1d20d0040e1cf130de5](https://github.com/fulgur-rs/fulgur/commit/8fabbca271313c56ef48f1d20d0040e1cf130de5)
- [https://github.com/fulgur-rs/fulgur/pull/602](https://github.com/fulgur-rs/fulgur/pull/602)

## Related threats

- [fulgur denial of service via unbudgeted CSS named-string values](https://junglewise.ai/threats/cve-2026-68539-fulgur-converts-untrusted-html-css-into-pdf-commonly-on-a-server)
- [fulgur unbounded CSS counters expansion in generated content](https://junglewise.ai/threats/cve-2026-68538-fulgur-converts-untrusted-html-css-into-pdf-commonly-on-a-server)