How severe is CVE-2026-44431?

CVE-2026-44431 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 low, integrity none, and availability none.

Is CVE-2026-44431 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-44431?

CVE-2026-44431 affects Python Urllib3. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-44431?

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

Does CVE-2026-44431 have an EU (EUVD) identifier?

Yes. CVE-2026-44431 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30046.

When was CVE-2026-44431 published?

CVE-2026-44431 was published on 2026-05-13 and last updated on 2026-06-26.

CVE-2026-44431

CVE-2026-44431 is a medium-severity vulnerability in Python Urllib3 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 8.2
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30046
Weakness: CWE-200
Affected product: Python Urllib3
Published: 2026-05-13
Last modified: 2026-06-26

Description

urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive headers. This vulnerability is fixed in 2.7.0.

Frequently asked questions

What is CVE-2026-44431?: urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive headers. This vulnerability is fixed in 2.7.0.
How severe is CVE-2026-44431?: CVE-2026-44431 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 low, integrity none, and availability none.
Is CVE-2026-44431 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-44431?: CVE-2026-44431 affects Python Urllib3. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-44431?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-44431 have an EU (EUVD) identifier?: Yes. CVE-2026-44431 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30046.
When was CVE-2026-44431 published?: CVE-2026-44431 was published on 2026-05-13 and last updated on 2026-06-26.

References

Affected products (1)

cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*

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