How severe is CVE-2023-39663?

CVE-2023-39663 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-2023-39663 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-39663?

CVE-2023-39663 affects Mathjax. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-39663?

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-2023-39663 published?

CVE-2023-39663 was published on 2023-08-29 and last updated on 2026-06-17.

CVE-2023-39663

CVE-2023-39663 is a high-severity vulnerability in Mathjax 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-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Mathjax
Published: 2023-08-29
Last modified: 2026-06-17

Description

Mathjax up to v2.7.9 was discovered to contain two Regular expression Denial of Service (ReDoS) vulnerabilities in MathJax.js via the components pattern and markdownPattern. NOTE: the vendor disputes this because the regular expressions are not applied to user input; thus, there is no risk.

Frequently asked questions

What is CVE-2023-39663?: Mathjax up to v2.7.9 was discovered to contain two Regular expression Denial of Service (ReDoS) vulnerabilities in MathJax.js via the components pattern and markdownPattern. NOTE: the vendor disputes this because the regular expressions are not applied to user input; thus, there is no risk.
How severe is CVE-2023-39663?: CVE-2023-39663 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-2023-39663 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-39663?: CVE-2023-39663 affects Mathjax. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-39663?: 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-2023-39663 published?: CVE-2023-39663 was published on 2023-08-29 and last updated on 2026-06-17.

References

https://github.com/mathjax/MathJax/issues/3074

Affected products (1)

cpe:2.3:a:mathjax:mathjax:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

203.192.232.180 (ipv4-addr)