How severe is CVE-2020-28493?

CVE-2020-28493 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2020-28493 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28493?

CVE-2020-28493 primarily affects Palletsprojects Jinja. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-28493?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-28493 published?

CVE-2020-28493 was published on 2021-02-01 and last updated on 2026-06-17.

CVE-2020-28493

CVE-2020-28493 is a medium-severity vulnerability in Palletsprojects Jinja with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Palletsprojects Jinja
Published: 2021-02-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-28493?: 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.
How severe is CVE-2020-28493?: CVE-2020-28493 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2020-28493 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28493?: CVE-2020-28493 primarily affects Palletsprojects Jinja. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-28493?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-28493 published?: CVE-2020-28493 was published on 2021-02-01 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:palletsprojects:jinja:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

More vulnerabilities in Palletsprojects Jinja

CVE-2025-27516 — High (CVSS 8.8): Jinja is an extensible templating engine. Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts…
CVE-2024-56201 — High (CVSS 8.8): Jinja is an extensible templating engine. In versions on the 3.x branch prior to 3.1.5, a bug in the Jinja compiler…
CVE-2016-10745 — High (CVSS 8.6): In Pallets Jinja before 2.8.1, str.format allows a sandbox escape.
CVE-2019-10906 — High (CVSS 8.6): In Pallets Jinja before 2.10.1, str.format_map allows a sandbox escape.
CVE-2024-56326 — High (CVSS 7.8): Jinja is an extensible templating engine. Prior to 3.1.5, An oversight in how the Jinja sandboxed environment detects…
CVE-2024-34064 — Medium (CVSS 5.4): Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing…

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