Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states "Warning: http.server is not recommended for production. It only implements basic security checks."

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.01395.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Fedoraproject Subscribe
Fedora Subscribe
Python Subscribe
Python Subscribe
Redhat Subscribe
Enterprise Linux Subscribe
Rhel Software Collections Subscribe

Configuration 1 [-]

OR cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha2:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha3:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha4:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha5:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha6:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:alpha7:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:beta1:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:beta2:*:*:*:*:*:*
cpe:2.3:a:python:python:3.11.0:beta3:*:*:*:*:*:*

Configuration 2 [-]

OR cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
Package CPE Advisory Released Date
Red Hat Enterprise Linux 8
python3-0:3.6.8-48.el8_7.1 cpe:/a:redhat:enterprise_linux:8 RHSA-2023:0833 2023-02-21T00:00:00Z
python38:3.8-8080020221221151857.0d9ba776 cpe:/a:redhat:enterprise_linux:8 RHSA-2023:2763 2023-05-16T00:00:00Z
python38-devel:3.8-8080020221221151857.0d9ba776 cpe:/a:redhat:enterprise_linux:8 RHSA-2023:2763 2023-05-16T00:00:00Z
python39:3.9-8080020221221152015.aed85c85 cpe:/a:redhat:enterprise_linux:8 RHSA-2023:2764 2023-05-16T00:00:00Z
python39-devel:3.9-8080020221221152015.aed85c85 cpe:/a:redhat:enterprise_linux:8 RHSA-2023:2764 2023-05-16T00:00:00Z
python3-0:3.6.8-48.el8_7.1 cpe:/o:redhat:enterprise_linux:8 RHSA-2023:0833 2023-02-21T00:00:00Z
Red Hat Enterprise Linux 9
python3.9-0:3.9.14-1.el9 cpe:/a:redhat:enterprise_linux:9 RHSA-2022:8353 2022-11-15T00:00:00Z
python3.9-0:3.9.14-1.el9 cpe:/o:redhat:enterprise_linux:9 RHSA-2022:8353 2022-11-15T00:00:00Z
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-python38-python-0:3.8.14-1.el7 cpe:/a:redhat:rhel_software_collections:3::el7 RHSA-2022:6766 2022-10-03T00:00:00Z

No data.

Advisories
Source ID Title
Debian DLA Debian DLA DLA-3966-1 pypy3 security update
Debian DLA Debian DLA DLA-3980-1 python3.9 security update
Ubuntu USN Ubuntu USN USN-5629-1 Python vulnerability
Ubuntu USN Ubuntu USN USN-5888-1 Python vulnerabilities
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://bugs.python.org/issue43223 cve-icon cve-icon
https://github.com/python/cpython/pull/24848 cve-icon cve-icon
https://github.com/python/cpython/pull/93879 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2024/11/msg00024.html cve-icon
https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2TRINJE3INWDVIHIABW4L2NP3RUSK7BJ/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LTSPFIULY2GZJN3QYNFVM4JSU6H4D6J/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5OABQ5CMPQETJLFHROAXDIDXCMDTNVYG/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DISZAFSIQ7IAPAEQTC7G2Z5QUA2V2PSW/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HPX4XHT2FGVQYLY2STT2MRVENILNZTTU/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I3MQT5ZE3QH5PVDJMERTBOCILHK35CBE/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IFGV7P2PYFBMK32OKHCAC2ZPJQV5AUDF/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRGKPYA5YHIXQAMRIXO5DSCX7D4UUW4Q/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OKYE2DOI2X7WZXAWTQJZAXYIWM37HDCY/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QLE5INSVJUZJGY5OJXV6JREXWD7UDHYN/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G66SRWUM36ENQ3X6LAIG7HAB27D4XJ/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TZEPOPUFC42KXXSLFPZ47ZZRGPOR7SQE/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXF6MQ74HVIDDSR5AE2UDR24I6D4FEPC/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X46T4EFTIBXZRYTGASBDEZGYJINH2OWV/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2021-28861 cve-icon
https://security.gentoo.org/glsa/202305-02 cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2021-28861 cve-icon
History

Wed, 17 Dec 2025 22:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}

Mon, 03 Nov 2025 22:30:00 +0000

Type Values Removed Values Added
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2025-12-17T21:30:32.380Z

Reserved: 2021-03-19T00:00:00.000Z

Link: CVE-2021-28861

cve-icon Vulnrichment

Updated: 2025-11-03T21:44:41.631Z

cve-icon NVD

Status : Modified

Published: 2022-08-23T01:15:07.617

Modified: 2025-12-17T22:15:56.490

Link: CVE-2021-28861

cve-icon Redhat

Severity : Moderate

Publid Date: 2022-08-22T00:00:00Z

Links: CVE-2021-28861 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses