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Fencer Vulns
high 7.1

CVE-2020-15138 json

Cross-Site Scripting in Prism

published 2020-08-07 6 y ago modified 2026-07-08 4 mo ago also GHSA-wvhm-4hhf-97x9 , EUVD-2020-0649

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

Prism is vulnerable to Cross-Site Scripting. The easing preview of the Previewers plugin has an XSS vulnerability that allows attackers to execute arbitrary code in Safari and Internet Explorer. This impacts all Safari and Internet Explorer users of Prism >=v1.1.0 that use the _Previewers_ plugin (>=v1.10.0) or the _Previewer: Easing_ plugin (v1.1.0 to v1.9.0). This problem is fixed in version 1.21.0. To workaround the issue without upgrading, disable the easing preview on all impacted code blocks. You need Prism v1.10.0 or newer to apply this workaround.

Patch / fix

  • npm prismjs 1.21.0
  • prismjs previewers 1.21.0
  • node-prismjs Debian 14, Debian 13, Debian 12 1.11.0+dfsg-4

debian advisories DEBIAN-CVE-2020-15138

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-2020-15138 updated cvss 7.5

nodejs-prismjs: xss vulnerability that allows attackers to execute arbitrary code

  • Red Hat OpenShift Service Mesh 1 servicemesh-grafana, servicemesh-grafana-prometheus Red Hat Ceph Storage 3 grafana Red Hat OpenShift Container Platform 3.11 openshift3/grafana Red Hat OpenShift Container Platform 4 openshift4/ose-grafana
    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

2.04% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:L
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:N/I:P/A:N
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L

Affected packages

ecosystem package affected fixed in
npm prismjs
>=1.1.0, <1.21.0
1.21.0

Affected products

  • PrismJS prism

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

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.