How severe is CVE-2023-4241?

CVE-2023-4241 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-4241 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-4241?

CVE-2023-4241 affects Cloudflare Lol-html. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-4241?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-4241 published?

CVE-2023-4241 was published on 2023-08-16 and last updated on 2026-06-17.

CVE-2023-4241

CVE-2023-4241 is a high-severity vulnerability in Cloudflare Lol-html with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cloudflare Lol-html
Published: 2023-08-16
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2023-4241?: lol-html can cause panics on certain HTML inputs. Anyone processing arbitrary 3rd party HTML with the library is affected.
How severe is CVE-2023-4241?: CVE-2023-4241 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-4241 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-4241?: CVE-2023-4241 affects Cloudflare Lol-html. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-4241?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-4241 published?: CVE-2023-4241 was published on 2023-08-16 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:cloudflare:lol-html:*:*:*:*:*:rust:*:*

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