CVE-2023-4241 — lol-html can cause panics on certain HTML inputs

lol-html can cause panics on certain HTML inputs. Anyone processing arbitrary 3rd party HTML with the library is affected.

01What is this vulnerability?

lol-html can cause panics on certain HTML inputs. Anyone processing arbitrary 3rd party HTML with the library is affected.

02Affected products

Vendor	Product	Versions
Cloudflare	lol	html — 0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-08-16T10:13:12.564Z
• Last modified: 2024-10-02T16:12:50.008Z

09References

• github.com — https://github.com/cloudflare/lol-html/security/advisories/GHSA-c3x7-354f-4p2x