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Fencer Vulns
critical 9.8

CVE-2020-14001 json

Unintended read access in kramdown gem

published 2020-07-17 6 y ago modified 2026-06-17 4 mo ago also GHSA-mqm2-cgpr-p4m6 , EUVD-2020-0635

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.6%
EPSS 4.6% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

The kramdown gem before 2.3.0 for Ruby processes the template option inside Kramdown documents by default, which allows unintended read access (such as template="/etc/passwd") or unintended embedded Ruby code execution (such as a string that begins with template="string://<%= `). NOTE: kramdown is used in Jekyll, GitLab Pages, GitHub Pages, and Thredded Forum.

Patch / fix

  • rubygems kramdown 2.3.0
  • kramdown_project kramdown 2.3.0
  • ruby-kramdown Debian 14, Debian 13, Debian 12 2.3.0-3

debian advisories DEBIAN-CVE-2020-14001

  • ruby-kramdown Ubuntu 20.04 LTS 1.17.0-4ubuntu0.1

ubuntu advisories UBUNTU-CVE-2020-14001

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rubygem-kramdown SLE High Availability Extension 15 SP4, SLE High Availability Extension 15 SP3, SLE High Availability Extension 15 SP2 +4 more 1.15.0-150000.3.3.1

suse advisories SUSE-SU-2022:3259-1

  • rubygem-kramdown openSUSE Tumbleweed 2.4.0-1.17
  • rubygem-kramdown openSUSE Tumbleweed 2.4.0-1.15
  • rubygem-kramdown openSUSE Tumbleweed 2.4.0-1.12
  • rubygem-kramdown openSUSE Tumbleweed 2.4.0-1.1
  • ruby3.2-rubygem-kramdown openSUSE Tumbleweed 2.4.0-1.8

opensuse advisories openSUSE-SU-2026:10352-1openSUSE-SU-2025:15119-1openSUSE-SU-2024:14170-1openSUSE-SU-2024:12038-1openSUSE-SU-2024:13161-1

  • icinga2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 2.11.3-r1

alpine advisories ALPINE-CVE-2020-14001

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2020-14001 updated cvss 9.1

rubygem-kramdown: processing template options inside documents allows unintended read access or embedded Ruby code execution

  • Red Hat All currently supported Red Hat products
    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

4.56% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
rubygems kramdown
<2.3.0
2.3.0

Classification

Weakness

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.