01 Record

CVE-2021-28861

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.

MediumPUBLISHEDCNA: mitre

CNA base score6.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

View raw JSON

02 Description

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.

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

2.70% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 85.7% of scored records. A rank, not a probability.

NVD base score

7.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-10-14.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2022-08-23 00:00Z4 YR AGO

Last updated

2026-10-14 11:39Z15 DAYS AGO

Reserved

2021-03-19

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 6.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Weaknesses

CWE-601URL Redirection to Untrusted Site ('Open Redirect')Base

Data version

5.2

Document digest

a73c76465cfbb21226e1cfa4e10c3f3def7b717362765d328749df98290e8a2b

05 Affected products

VendorProductVersionsPlatforms

fedoraprojectfedoraNot specified—

pythonpythonNot specified—

redhatenterprise_linuxNot specified—

redhatrhel_software_collectionsNot specified—

06 References

bugs.python.orghttps://bugs.python.org/issue43223
github.comhttps://github.com/python/cpython/pull/93879
github.comhttps://github.com/python/cpython/pull/24848
lists.fedoraproject.orgFEDORA-2022-f511f8f58bhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OKYE2DOI2X7WZXAWTQJZAXYIWM37HDCY/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-7fff0f2b0bhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LTSPFIULY2GZJN3QYNFVM4JSU6H4D6J/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-a27e239f5ahttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G66SRWUM36ENQ3X6LAIG7HAB27D4XJ/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-a2be4bd5d8https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DISZAFSIQ7IAPAEQTC7G2Z5QUA2V2PSW/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-15f1aa7dc7https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QLE5INSVJUZJGY5OJXV6JREXWD7UDHYN/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-fde69532dfhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HPX4XHT2FGVQYLY2STT2MRVENILNZTTU/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-61d8e8d880https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X46T4EFTIBXZRYTGASBDEZGYJINH2OWV/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-4ac2e16969https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRGKPYA5YHIXQAMRIXO5DSCX7D4UUW4Q/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-2173709172https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I3MQT5ZE3QH5PVDJMERTBOCILHK35CBE/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-01d5789c08https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2TRINJE3INWDVIHIABW4L2NP3RUSK7BJ/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-d1682fef04https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXF6MQ74HVIDDSR5AE2UDR24I6D4FEPC/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-79843dfb3chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IFGV7P2PYFBMK32OKHCAC2ZPJQV5AUDF/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-20116fb6aahttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TZEPOPUFC42KXXSLFPZ47ZZRGPOR7SQE/vendor-advisory
lists.fedoraproject.orgFEDORA-2022-7ca361a226https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5OABQ5CMPQETJLFHROAXDIDXCMDTNVYG/vendor-advisory
security.gentoo.orgGLSA-202305-02https://security.gentoo.org/glsa/202305-02vendor-advisory
lists.debian.orghttps://lists.debian.org/debian-lts-announce/2024/12/msg00000.html
lists.debian.orghttps://lists.debian.org/debian-lts-announce/2024/11/msg00024.html
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-398330.html

07 Fixed in

AlmaLinux 8

platform-python
Fixed in 3.6.8-48.el8_7.1.alma
platform-python-debug
Fixed in 3.6.8-48.el8_7.1.alma
platform-python-devel
Fixed in 3.6.8-48.el8_7.1.alma
python3-idle
Fixed in 3.6.8-48.el8_7.1.alma
python3-libs
Fixed in 3.6.8-48.el8_7.1.alma
python3-test
Fixed in 3.6.8-48.el8_7.1.alma
python3-tkinter
Fixed in 3.6.8-48.el8_7.1.alma
python38
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-Cython
Fixed

A version is affected if any line below covers it.
- Affected before 0.29.14-4.module_el8.6.0+2778+cd494b30
- Affected before 0.29.14-4.module_el8.6.0+3163+f4472775
python38-PyMySQL
Fixed in 0.10.1-1.module_el8.6.0+2778+cd494b30
python38-asn1crypto
Fixed in 1.2.0-3.module_el8.6.0+2778+cd494b30
python38-atomicwrites
Fixed in 1.3.0-8.module_el8.6.0+2778+cd494b30
python38-attrs
Fixed in 19.3.0-3.module_el8.6.0+2778+cd494b30
python38-babel
Fixed in 2.7.0-11.module_el8.6.0+2778+cd494b30
python38-cffi
Fixed

A version is affected if any line below covers it.
- Affected before 1.13.2-3.module_el8.6.0+2778+cd494b30
- Affected before 1.13.2-3.module_el8.6.0+3163+f4472775
python38-chardet
Fixed in 3.0.4-19.module_el8.6.0+2778+cd494b30
python38-cryptography
Fixed

A version is affected if any line below covers it.
- Affected before 2.8-3.module_el8.6.0+2778+cd494b30
- Affected before 2.8-3.module_el8.6.0+3163+f4472775
python38-debug
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-devel
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-idle
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-idna
Fixed in 2.8-6.module_el8.6.0+2778+cd494b30
python38-jinja2
Fixed in 2.11.3-1.module_el8.7.0+3344+99a6a656
python38-libs
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-lxml
Fixed

A version is affected if any line below covers it.
- Affected before 4.4.1-7.module_el8.6.0+2778+cd494b30
- Affected before 4.4.1-7.module_el8.6.0+3163+f4472775
python38-markupsafe
Fixed

A version is affected if any line below covers it.
- Affected before 1.1.1-6.module_el8.6.0+2778+cd494b30
- Affected before 1.1.1-6.module_el8.6.0+3163+f4472775
python38-mod_wsgi
Fixed in 4.6.8-4.module_el8.7.0+3344+99a6a656
python38-more-itertools
Fixed in 7.2.0-5.module_el8.6.0+2778+cd494b30
python38-numpy
Fixed

A version is affected if any line below covers it.
- Affected before 1.17.3-6.module_el8.6.0+2778+cd494b30
- Affected before 1.17.3-6.module_el8.6.0+3163+f4472775
python38-numpy-doc
Fixed in 1.17.3-6.module_el8.6.0+2778+cd494b30
python38-numpy-f2py
Fixed

A version is affected if any line below covers it.
- Affected before 1.17.3-6.module_el8.6.0+2778+cd494b30
- Affected before 1.17.3-6.module_el8.6.0+3163+f4472775
python38-packaging
Fixed in 19.2-3.module_el8.6.0+2778+cd494b30
python38-pip
Fixed in 19.3.1-6.module_el8.7.0+3344+99a6a656
python38-pip-wheel
Fixed in 19.3.1-6.module_el8.7.0+3344+99a6a656
python38-pluggy
Fixed in 0.13.0-3.module_el8.6.0+2778+cd494b30
python38-ply
Fixed in 3.11-10.module_el8.6.0+2778+cd494b30
python38-psutil
Fixed

A version is affected if any line below covers it.
- Affected before 5.6.4-4.module_el8.6.0+2778+cd494b30
- Affected before 5.6.4-4.module_el8.6.0+3163+f4472775
python38-psycopg2
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-psycopg2-doc
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-psycopg2-tests
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-py
Fixed in 1.8.0-8.module_el8.6.0+2778+cd494b30

67 further packages in AlmaLinux 8 not shown (first 40 listed).

AlmaLinux 9

python-unversioned-command
Fixed in 3.9.14-1.el9
python3
Fixed in 3.9.14-1.el9
python3-debug
Fixed in 3.9.14-1.el9
python3-devel
Fixed in 3.9.14-1.el9
python3-idle
Fixed in 3.9.14-1.el9
python3-libs
Fixed in 3.9.14-1.el9
python3-test
Fixed in 3.9.14-1.el9
python3-tkinter
Fixed in 3.9.14-1.el9

CloudLinux 8

platform-python
Fixed in 3.6.8-48.el8_7.1.alma
platform-python-debug
Fixed in 3.6.8-48.el8_7.1.alma
platform-python-devel
Fixed in 3.6.8-48.el8_7.1.alma
python3-idle
Fixed in 3.6.8-48.el8_7.1.alma
python3-libs
Fixed in 3.6.8-48.el8_7.1.alma
python3-test
Fixed in 3.6.8-48.el8_7.1.alma
python3-tkinter
Fixed in 3.6.8-48.el8_7.1.alma
python38
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-Cython
Fixed

A version is affected if any line below covers it.
- Affected before 0.29.14-4.module_el8.6.0+2778+cd494b30
- Affected before 0.29.14-4.module_el8.6.0+3163+f4472775
python38-PyMySQL
Fixed in 0.10.1-1.module_el8.6.0+2778+cd494b30
python38-asn1crypto
Fixed in 1.2.0-3.module_el8.6.0+2778+cd494b30
python38-atomicwrites
Fixed in 1.3.0-8.module_el8.6.0+2778+cd494b30
python38-attrs
Fixed in 19.3.0-3.module_el8.6.0+2778+cd494b30
python38-babel
Fixed in 2.7.0-11.module_el8.6.0+2778+cd494b30
python38-cffi
Fixed

A version is affected if any line below covers it.
- Affected before 1.13.2-3.module_el8.6.0+2778+cd494b30
- Affected before 1.13.2-3.module_el8.6.0+3163+f4472775
python38-chardet
Fixed in 3.0.4-19.module_el8.6.0+2778+cd494b30
python38-cryptography
Fixed

A version is affected if any line below covers it.
- Affected before 2.8-3.module_el8.6.0+2778+cd494b30
- Affected before 2.8-3.module_el8.6.0+3163+f4472775
python38-debug
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-devel
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-idle
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-idna
Fixed in 2.8-6.module_el8.6.0+2778+cd494b30
python38-jinja2
Fixed in 2.11.3-1.module_el8.7.0+3344+99a6a656
python38-libs
Fixed in 3.8.16-1.module_el8.8.0+3482+d5d93a3e
python38-lxml
Fixed

A version is affected if any line below covers it.
- Affected before 4.4.1-7.module_el8.6.0+2778+cd494b30
- Affected before 4.4.1-7.module_el8.6.0+3163+f4472775
python38-markupsafe
Fixed

A version is affected if any line below covers it.
- Affected before 1.1.1-6.module_el8.6.0+2778+cd494b30
- Affected before 1.1.1-6.module_el8.6.0+3163+f4472775
python38-mod_wsgi
Fixed in 4.6.8-4.module_el8.7.0+3344+99a6a656
python38-more-itertools
Fixed in 7.2.0-5.module_el8.6.0+2778+cd494b30
python38-numpy
Fixed

A version is affected if any line below covers it.
- Affected before 1.17.3-6.module_el8.6.0+2778+cd494b30
- Affected before 1.17.3-6.module_el8.6.0+3163+f4472775
python38-numpy-doc
Fixed in 1.17.3-6.module_el8.6.0+2778+cd494b30
python38-numpy-f2py
Fixed

A version is affected if any line below covers it.
- Affected before 1.17.3-6.module_el8.6.0+2778+cd494b30
- Affected before 1.17.3-6.module_el8.6.0+3163+f4472775
python38-packaging
Fixed in 19.2-3.module_el8.6.0+2778+cd494b30
python38-pip
Fixed in 19.3.1-6.module_el8.7.0+3344+99a6a656
python38-pip-wheel
Fixed in 19.3.1-6.module_el8.7.0+3344+99a6a656
python38-pluggy
Fixed in 0.13.0-3.module_el8.6.0+2778+cd494b30
python38-ply
Fixed in 3.11-10.module_el8.6.0+2778+cd494b30
python38-psutil
Fixed

A version is affected if any line below covers it.
- Affected before 5.6.4-4.module_el8.6.0+2778+cd494b30
- Affected before 5.6.4-4.module_el8.6.0+3163+f4472775
python38-psycopg2
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-psycopg2-doc
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-psycopg2-tests
Fixed in 2.8.4-4.module_el8.7.0+3344+99a6a656
python38-py
Fixed in 1.8.0-8.module_el8.6.0+2778+cd494b30

67 further packages in CloudLinux 8 not shown (first 40 listed).

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

CloudLinux 9

python-unversioned-command
Fixed in 3.9.14-1.el9
python3
Fixed in 3.9.14-1.el9
python3-debug
Fixed in 3.9.14-1.el9
python3-devel
Fixed in 3.9.14-1.el9
python3-idle
Fixed in 3.9.14-1.el9
python3-libs
Fixed in 3.9.14-1.el9
python3-test
Fixed in 3.9.14-1.el9
python3-tkinter
Fixed in 3.9.14-1.el9

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Debian 12

pypy3
Fixed in 7.3.10+dfsg-1
python3.11
Fixed in 3.11.0~b4-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

pypy3
Fixed in 7.3.10+dfsg-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

pypy3
Fixed in 7.3.10+dfsg-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

python3.10
Fixed in 3.10.6-1~22.04.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

python3.5
Fixed in 3.5.2-2ubuntu0~16.04.13+esm5
Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

python3.9
Fixed in 3.9.5-3ubuntu0~20.04.1+esm1
Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.