How severe is CVE-2020-23478?

CVE-2020-23478 has a CVSS 3.x base score of 7.5, rated high 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 high.

Is CVE-2020-23478 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-23478?

CVE-2020-23478 affects Leoeditor Leo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-23478?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-23478 published?

CVE-2020-23478 was published on 2021-09-22 and last updated on 2026-06-17.

CVE-2020-23478

CVE-2020-23478 is a high-severity vulnerability in Leoeditor Leo with a CVSS 3.x base score of 7.5. 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-697.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-697
Affected product: Leoeditor Leo
Published: 2021-09-22
Last modified: 2026-06-17

Description

Leo Editor v6.2.1 was discovered to contain a regular expression denial of service (ReDoS) vulnerability in the component plugins/importers/dart.py.

Frequently asked questions

What is CVE-2020-23478?: Leo Editor v6.2.1 was discovered to contain a regular expression denial of service (ReDoS) vulnerability in the component plugins/importers/dart.py.
How severe is CVE-2020-23478?: CVE-2020-23478 has a CVSS 3.x base score of 7.5, rated high 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 high.
Is CVE-2020-23478 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-23478?: CVE-2020-23478 affects Leoeditor Leo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-23478?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-23478 published?: CVE-2020-23478 was published on 2021-09-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:leoeditor:leo:6.2.1:*:*:*:*:*:*:*

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