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Fencer Vulns
medium 6.8

CVE-2020-26298 json

Injection in Redcarpet

published 2021-01-11 5 y ago modified 2026-07-08 4 mo ago also GHSA-q3wr-qw3g-3p4h , EUVD-2021-0511

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

Redcarpet is a Ruby library for Markdown processing. In Redcarpet before version 3.5.1, there is an injection vulnerability which can enable a cross-site scripting attack. In affected versions no HTML escaping was being performed when processing quotes. This applies even when the `:escape_html` option was being used. This is fixed in version 3.5.1 by the referenced commit.

Patch / fix

  • rubygems redcarpet 3.5.1
  • redcarpet_project redcarpet 3.5.1
  • ruby-redcarpet Debian 14, Debian 13, Debian 12 3.5.1-1

debian advisories DEBIAN-CVE-2020-26298

  • kibana OpenStack Cloud Crowbar 9, OpenStack Cloud 9 4.6.6-4.12.1
  • influxdb OpenStack Cloud Crowbar 9, OpenStack Cloud 9 1.3.8-4.6.1
  • rubygem-puma OpenStack Cloud Crowbar 9 2.16.0-4.15.1
  • ardana-ansible OpenStack Cloud 9 9.0+git.1628097238.f6cbb0e-3.29.1
  • ardana-monasca OpenStack Cloud 9 9.0+git.1627995376.30bdf85-3.25.1
  • openstack-nova OpenStack Cloud Crowbar 9, OpenStack Cloud 9 18.3.1~dev91-3.40.1
  • python-eventlet OpenStack Cloud Crowbar 9, OpenStack Cloud 9 0.20.0-8.3.1
  • openstack-cinder OpenStack Cloud Crowbar 9, OpenStack Cloud 9 13.0.10~dev23-3.31.2

suse advisories SUSE-SU-2021:3729-1SUSE-SU-2021:3728-1

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-2020-26298 updated cvss 6.8

rubygem-redcarpet: does not escape HTML when processing quotes which could result in XSS vulnerability

  • Red Hat 3scale API Management Platform 2 redcarpet redcarpet
    affected: no fix available

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

1.59% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N
GitHub 3.1 6.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
rubygems redcarpet
<3.5.1
3.5.1

Affected products

  • vmg redcarpet

Classification

Weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
  • 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.