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Fencer Vulns
high 7.4

CVE-2021-32723 json

Regular Expression Denial of Service (ReDoS) in Prism

published 2021-06-28 5 y ago modified 2026-07-08 4 mo ago also GHSA-gj77-59wh-66hg , EUVD-2021-1326

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm prismjs 1.24.0
  • prismjs prism 1.24.0
  • oracle application_express 21.1.4

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-32723 updated cvss 6.5

npm-prismjs: a malicious (long) string will take a long time to highlight may result in ReDoS

  • Red Hat OpenShift Service Mesh 1 servicemesh-grafana, servicemesh-grafana-prometheus
    affected: workaround, no fix planned “As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text.”
  • Red Hat OpenShift Service Mesh 2.0 servicemesh-grafana, servicemesh-grafana-prometheus Red Hat Advanced Cluster Security 3 rox
    affected: workaround, no fix available “As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text.”
  • Red Hat Ceph Storage 3 grafana Red Hat OpenShift Container Platform 3.11 openshift3/grafana
    affected: workaround, no fix planned “As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text.”
  • Red Hat OpenShift Container Platform 4 openshift4/ose-grafana
    affected: workaround, no fix available “As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text.”
  • Red Hat Ceph Storage 4 rhceph/rhceph-4-dashboard-rhel8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.42% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm prismjs
<1.24.0
1.24.0

Affected products

  • PrismJS prism

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.