How severe is CVE-2021-32723?

CVE-2021-32723 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-32723 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-32723?

CVE-2021-32723 primarily affects Prismjs Prism. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-32723?

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-2021-32723 published?

CVE-2021-32723 was published on 2021-06-28 and last updated on 2026-06-17.

CVE-2021-32723

CVE-2021-32723 is a high-severity vulnerability in Prismjs Prism with a CVSS 3.x base score of 7.4. 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-400.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v2: 4.3
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Prismjs Prism
Published: 2021-06-28
Last modified: 2026-06-17

Description

Prism is a syntax highlighting library. Some languages before 1.24.0 are vulnerable to Regular Expression Denial of Service (ReDoS). When Prism is used to highlight untrusted (user-given) text, an attacker can craft a string that will take a very very long time to highlight. This problem has been fixed in Prism v1.24. As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text. Other languages are not affected and can be used to highlight untrusted text.

Frequently asked questions

What is CVE-2021-32723?: Prism is a syntax highlighting library. Some languages before 1.24.0 are vulnerable to Regular Expression Denial of Service (ReDoS). When Prism is used to highlight untrusted (user-given) text, an attacker can craft a string that will take a very very long time to highlight. This problem has been fixed in Prism v1.24. As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text. Other languages are not affected and can be used to highlight untrusted text.
How severe is CVE-2021-32723?: CVE-2021-32723 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-32723 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-32723?: CVE-2021-32723 primarily affects Prismjs Prism. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-32723?: 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-2021-32723 published?: CVE-2021-32723 was published on 2021-06-28 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:prismjs:prism:*:*:*:*:*:node.js:*:*
cpe:2.3:a:oracle:application_express:*:*:*:*:*:*:*:*

More vulnerabilities in Prismjs Prism

CVE-2022-23647 — High (CVSS 7.5): Prism is a syntax highlighting library. Starting with version 1.14.0 and prior to version 1.27.0, Prism's command line…
CVE-2021-23341 — High (CVSS 7.5): The package prismjs before 1.23.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the…
CVE-2021-3801 — Medium (CVSS 6.5): prism is vulnerable to Inefficient Regular Expression Complexity
CVE-2024-53382 — Medium (CVSS 4.9): Prism (aka PrismJS) through 1.29.0 allows DOM Clobbering (with resultant XSS for untrusted input that contains HTML but…

All CVEs affecting Prismjs Prism →

Other CWE-400 (Uncontrolled Resource Consumption) vulnerabilities

CVE-2026-46775 — Critical (CVSS 9.9): Vulnerability in Oracle REST Data Services (component: Core). Supported versions that are affected are 24.2.0-26.1.0.…
CVE-2025-61303 — Critical (CVSS 9.8): Hatching Triage Sandbox Windows 10 build 2004 (2025-08-14) and Windows 10 LTSC 2021(2025-08-14) contains a…
CVE-2025-43193 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.6, macOS Sonoma 14.7.7,…
CVE-2025-24269 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4. An app may be able to…
CVE-2025-24264 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in Safari 18.4, iOS 18.4 and iPadOS 18.4,…
CVE-2025-24260 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4, macOS Sonoma 14.7.5,…

Browse all CWE-400 (Uncontrolled Resource Consumption) vulnerabilities →