How severe is CVE-2026-4519?

CVE-2026-4519 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-4519 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4519?

CVE-2026-4519 primarily affects Python. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-4519?

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

Does CVE-2026-4519 have an EU (EUVD) identifier?

Yes. CVE-2026-4519 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13712.

When was CVE-2026-4519 published?

CVE-2026-4519 was published on 2026-03-20 and last updated on 2026-06-30.

CVE-2026-4519

CVE-2026-4519 is a low-severity vulnerability in Python with a CVSS 3.x base score of 3.3. 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-20.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v4: 7.0
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13712
Weakness: CWE-20
Affected product: Python
Published: 2026-03-20
Last modified: 2026-06-30

Description

The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().

Frequently asked questions

What is CVE-2026-4519?: The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().
How severe is CVE-2026-4519?: CVE-2026-4519 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-4519 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4519?: CVE-2026-4519 primarily affects Python. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-4519?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4519 have an EU (EUVD) identifier?: Yes. CVE-2026-4519 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13712.
When was CVE-2026-4519 published?: CVE-2026-4519 was published on 2026-03-20 and last updated on 2026-06-30.

References

Affected products (8)

cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

49.229.102.187 (ipv4-addr)
41.63.62.103 (ipv4-addr)
203.192.232.180 (ipv4-addr)
177.53.215.134 (ipv4-addr)
149.86.233.213 (ipv4-addr)
141.109.168.26 (ipv4-addr)
141.109.168.107 (ipv4-addr)
125.212.235.194 (ipv4-addr)