CVE-2020-28493

Name: CVE-2020-28493
Creator: NVD / NIST
Published: 2021-02-01T20:15:12.517+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 3.55%

Last modified Jun 17, 2026

CVE-2020-28493 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. EPSS estimates a 3.55% chance of exploitation in the next 30 days.

Description

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

3.55%

87.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Palletsprojects	Jinja	< 2.11.3
Fedoraproject	Fedora	33

References

https://github.com/pallets/jinja/blob/ab81fd9c277900c85da0c322a2ff9d68a235b2e6/src/jinja2/utils.py%23L20Broken Link
https://github.com/pallets/jinja/pull/1343Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVAKCOO7VBVUBM3Q6CBBTPBFNP5NDXF4/
https://security.gentoo.org/glsa/202107-19Third Party Advisory
https://snyk.io/vuln/SNYK-PYTHON-JINJA2-1012994Exploit, Third Party Advisory
https://github.com/pallets/jinja/blob/ab81fd9c277900c85da0c322a2ff9d68a235b2e6/src/jinja2/utils.py%23L20Broken Link
https://github.com/pallets/jinja/pull/1343Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVAKCOO7VBVUBM3Q6CBBTPBFNP5NDXF4/
https://security.gentoo.org/glsa/202107-19Third Party Advisory
https://snyk.io/vuln/SNYK-PYTHON-JINJA2-1012994Exploit, Third Party Advisory

Timeline

Published: Feb 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-28493?

How severe is CVE-2020-28493?

CVE-2020-28493 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 3.55% probability of exploitation in the next 30 days.

How do I fix CVE-2020-28493?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-28493?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST