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TI-2020-17297 Aliases CVE-2020-28493GHSA-g3rq-g295-4j3m

Regular expression denial of service (ReDoS) in jinja2

Priority LOW 30CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Partial Red Hat: 5 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

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.

Why it matters now

EPSS 0.03589 89th percentileScored 2026-11-07
Fix Partial jinja2: 2.11.3Jinja2 (PyPI): 2.11.3Red Hat: 5 advisoriesRed Hat: 5 fixed, 7 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—jinja20.0.0 and later; before 2.11.32.11.3Patch availableCNA
—Jinja2 (PyPI)before 2.11.32.11.3Patch availableGHSA-g3rq-g295-4j3m
  • jinja2 Vendor— Affected 0.0.0 and later; before 2.11.3 Fixed in 2.11.3 Patch available CNA
  • Jinja2 (PyPI) Vendor— Affected before 2.11.3 Fixed in 2.11.3 Patch available GHSA-g3rq-g295-4j3m

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:palletsprojects:jinja:*:*:*:*:*:*:*:*before 2.11.3Vulnerablepallets
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
  • cpe:2.3:a:palletsprojects:jinja:*:*:*:*:*:*:*:* Versions before 2.11.3 Vulnerable ·pallets
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject

Remediation

  • Fix · CNA jinja2 Fixed in 2.11.3
  • Fix · GHSA-g3rq-g295-4j3m Jinja2 (PyPI) Fixed in 2.11.3 Advisory →

Red Hat 5 advisories

  • RHSA-2021:4161 Released 2021-11-09 · Red Hat rating Moderate
    python-jinja2 security update
    • Red Hat Enterprise Linux AppStream (v. 8) python-jinja2-2.10.1-3.el8, python3-jinja2-2.10.1-3.el8
  • RHSA-2021:4162 Released 2021-11-09 · Red Hat rating Moderate
    python38:3.8 and python38-devel:3.8 security update
    • Red Hat CodeReady Linux Builder (v. 8) pytest-4.6.6-3.module+el8.4.0+8888+89bc7e79.src::python38-devel:3.8, python-atomicwrites-1.3.0-8.module+el8.4.0+8888+89bc7e79.src::python38-devel:3.8, python-attrs-19.3.0-3.module+el8.4.0+8888+89bc7e79.src::python38-devel:3.8 +15
    • Red Hat Enterprise Linux AppStream (v. 8) Cython-0.29.14-4.module+el8.4.0+8888+89bc7e79.src::python38:3.8, PyYAML-5.4.1-1.module+el8.5.0+10721+14d8e0d5.src::python38:3.8, babel-2.7.0-11.module+el8.5.0+11015+9c1c7c42.src::python38:3.8 +47
  • RHSA-2021:4151 Released 2021-11-09 · Red Hat rating Moderate
    python27:2.7 security update
    • Red Hat Enterprise Linux AppStream (v. 8) Cython-0.28.1-7.module+el8.1.0+3111+de3f2d8e.src::python27:2.7, PyYAML-3.12-16.module+el8.1.0+3111+de3f2d8e.src::python27:2.7, babel-2.5.1-10.module+el8.5.0+11014+88fc0d0b.noarch::python27:2.7 +47
Show 2 more Red Hat advisories
  • RHSA-2021:3252 Released 2021-08-24 · Red Hat rating Moderate
    python27 security update
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) python27-babel-0.9.6-10.el7, python27-python-2.7.18-3.el7, python27-python-babel-0.9.6-10.el7 +8
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.7) python27-babel-0.9.6-10.el7, python27-python-2.7.18-3.el7, python27-python-babel-0.9.6-10.el7 +8
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) python27-babel-0.9.6-10.el7, python27-python-2.7.18-3.el7, python27-python-babel-0.9.6-10.el7 +8
  • RHSA-2021:3254 Released 2021-08-24 · Red Hat rating Moderate
    rh-python38 security, bug fix, and enhancement update
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) rh-python38-babel-2.7.0-12.el7, rh-python38-python-3.8.11-2.el7, rh-python38-python-babel-2.7.0-12.el7 +14
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.7) rh-python38-babel-2.7.0-12.el7, rh-python38-python-3.8.11-2.el7, rh-python38-python-babel-2.7.0-12.el7 +14
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) rh-python38-babel-2.7.0-12.el7, rh-python38-python-3.8.11-2.el7, rh-python38-python-babel-2.7.0-12.el7 +14

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Ceph Storage 2AffectedNo fix planned: Out of support scope
Red Hat Ceph Storage 3AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat OpenStack Platform 13 (Queens)AffectedNo fix planned: Will not fix
Red Hat Quay 3AffectedNo fix yet
Red Hat Satellite 6AffectedNo fix yet
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:4162
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:4151, RHSA-2021:4161, RHSA-2021:4162
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:3252, RHSA-2021:3254
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.7)Fixed RHSA-2021:3252, RHSA-2021:3254
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:3252, RHSA-2021:3254
Not affected: 3 products
  • Red Hat Ansible Automation Platform 1.2
  • Red Hat Ansible Tower 3
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-28493
  2. 2026-10-03 Alias added: GHSA-g3rq-g295-4j3m

References

Patch 1

Advisory 4

Other 5

Sources

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