High 8.2Published May 13, 2026

CVE-2026-44431urllib3: Sensitive headers forwarded across origins in proxied low-level redirects

Updated under an hour ago (Oct 28, 2026, 4:50 AM ET)

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It affects urllib3 and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for urllib3

Exploited in the last 30 days

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.

CVSS: 8.2 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE): CWE-200
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jun 26, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

urllib3 urllib3 urllib3:urllib3 (from the name)	from 1.23, < 2.7.0	CNA record
python urllib3 python:urllib3	from 1.23 before 2.7.0	NVD

References

References

https://github.com/urllib3/urllib3/security/advisories/GHSA-qccp-gfcp-xxvc	x-refsource-confirm, mitigation, vendor-advisory
https://lists.debian.org/debian-lts-announce/2026/06/msg00040.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.