CVE-2020-11888

XSS in python-markdown2

6.1 MediumFix available

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

1.93%Up 0.5 points since Apr 14, 2021

What each source reports

NVD Score used 6.1

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: CVE-2020-11888
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness: CWE-79
Updated: 2026-11-02

CVE List No score

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: CVE-2020-11888
Updated: 2026-11-02

EUVDEUVD-2020-0105 No score

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: EUVD-2020-0105
Updated: 2026-11-03

GitHub AdvisoriesGHSA-fv3h-8x5j-pvgq 5.1

XSS in python-markdown2

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: GHSA-fv3h-8x5j-pvgq
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSV 6.1

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: CVE-2020-11888
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVDEBIAN-CVE-2020-11888 6.1

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: DEBIAN-CVE-2020-11888
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

Show 5 moreShow less

OSVGHSA-fv3h-8x5j-pvgq 5.1

XSS in python-markdown2

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: GHSA-fv3h-8x5j-pvgq
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSVUBUNTU-CVE-2020-11888 6.1

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: UBUNTU-CVE-2020-11888
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVopenSUSE-SU-2020:0651-1 No score

Security update for python-markdown2

This update for python-markdown2 fixes the following issues:

CVE-2020-11888: Fixed unsanitized input for cross-site scripting (boo#1171379)

Record: openSUSE-SU-2020:0651-1
Updated: 2026-11-02

OSVopenSUSE-SU-2020:0656-1 No score

Security update for python-markdown2

This update for python-markdown2 fixes the following issues:

CVE-2020-11888: Fixed unsanitized input for cross-site scripting (boo#1171379)

This update was imported from the openSUSE:Leap:15.1:Update update project.

Record: openSUSE-SU-2020:0656-1
Updated: 2026-11-02

OSVPYSEC-2020-65 No score

python-markdown2 through 2.3.8 allows XSS because element names are mishandled unless a \w+ match succeeds. For example, an attack might use elementname@ or elementname- with an onclick attribute.

Record: PYSEC-2020-65
Updated: 2026-11-02

Affected products

python-markdown2 project python-markdown2

Affected packages

Affected packages
Package	Affected	Fixed
`markdown2` PyPI	through 2.3.8	2.3.9
`python-markdown2` Debian:12	before 2.3.9-1	2.3.9-1
`python-markdown2` Debian:13	before 2.3.9-1	2.3.9-1
`python-markdown2` Debian:14	before 2.3.9-1	2.3.9-1
`markdown2` PyPI	before 2.3.9, plus listed versions 1.0.1.101.0.1.111.0.1.121.0.1.131.0.1.14 Show 33 moreShow less 1.0.1.151.0.1.161.0.1.171.0.1.181.0.1.191.0.1.61.0.1.71.0.1.81.0.1.91.1.01.1.11.2.01.3.01.3.11.4.01.4.11.4.22.0.02.0.12.1.02.2.02.2.12.2.22.2.32.3.02.3.12.3.22.3.32.3.42.3.52.3.62.3.72.3.8	2.3.9
`markdown2` PyPI	before 2.3.9, plus listed versions 1.0.1.61.0.1.71.0.1.81.0.1.91.0.1.10 Show 33 moreShow less 1.0.1.111.0.1.121.0.1.131.0.1.141.0.1.151.0.1.161.0.1.171.0.1.181.0.1.191.1.01.1.11.2.01.3.01.3.11.4.01.4.11.4.22.0.02.0.12.1.02.2.02.2.12.2.22.2.32.3.02.3.12.3.22.3.32.3.42.3.52.3.62.3.72.3.8	2.3.9
`python-markdown2` Ubuntu:20.04:LTS	All versions, plus listed versions 2.3.7-2	None known
`python-markdown2` openSUSE:Leap 15.1	before 2.3.7-lp151.2.3.1	2.3.7-lp151.2.3.1
`python-markdown2` SUSE:Package Hub 15 SP1	before 2.3.7-bp151.2.3.1	2.3.7-bp151.2.3.1

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-11888 is a medium vulnerability (CVSS 6.1) in Python-markdown2 Project Python-markdown2, published April 20, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.93%, the 80th percentile. Fixed in markdown2 2.3.9.

References

Show 14 moreShow less