synced 2 MIN AGO
01 Record

CVE-2026-21441

urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)

HighPUBLISHEDCNA: GitHub_M
CNA base score8.9 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
View raw JSON

02 Description

urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)

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.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • 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
2.92% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 86.5% of scored records. A rank, not a probability.
NVD base score
8.9 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD analysis status
Modified. NVD last modified this record on 2026-09-15.
Red Hat severity
Important. 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
2026-01-07 22:09Z9 MO AGO
Last updated
2026-09-17 12:04Z1 MO AGO
Reserved
2025-12-29
Assigning CNA
GitHub_M
Record state
PUBLISHED
Severity
High (CVSS 8.9)
CNA CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Weaknesses
  • CWE-409Improper Handling of Highly Compressed Data (Data Amplification)Base
Data version
5.2
Document digest
3bd090289641f3cea8ccd7b3237a51e6d3171116ec81bdd9dd5d6886167d4a2a

05 Affected products

VendorProductVersionsPlatforms
urllib3urllib3>= 1.22, < 2.6.3—

06 References

07 Fixed in

AlmaLinux 8

  • fence-agents-aliyun
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-all
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-amt-ws
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-apc
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-apc-snmp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-aws
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-azure-arm
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-bladecenter
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-brocade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-cisco-mds
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-cisco-ucs
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-common
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-compute
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-drac5
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-eaton-snmp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-emerson
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-eps
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-gce
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-heuristics-ping
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-hpblade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibm-powervs
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibm-vpc
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibmblade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ifmib
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-moonshot
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-mp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-ssh
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo2
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-intelmodular
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ipdu
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ipmilan
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-kdump
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-kubevirt
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-lpar
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-mpath
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-nutanix-ahv
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-openstack
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-redfish
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-rhevm
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-rsa
    Fixed in 4.2.1-129.el8_10.20

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

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • fence-agents-aliyun
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-all
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-amt-ws
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-apc
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-apc-snmp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-aws
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-azure-arm
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-bladecenter
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-brocade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-cisco-mds
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-cisco-ucs
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-common
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-compute
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-drac5
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-eaton-snmp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-emerson
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-eps
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-gce
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-heuristics-ping
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-hpblade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibm-powervs
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibm-vpc
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibmblade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ifmib
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-moonshot
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-mp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-ssh
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo2
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-intelmodular
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ipdu
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ipmilan
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-kdump
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-kubevirt
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-lpar
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-mpath
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-nutanix-ahv
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-openstack
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-redfish
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-rhevm
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-rsa
    Fixed in 4.10.0-98.el9_7.4

19 further packages in AlmaLinux 9 not shown (first 40 listed).

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • python3-urllib3
    Fixed in 1.26.19-2.el10_1.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • fence-agents-aliyun
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-all
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-amt-ws
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-apc
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-apc-snmp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-aws
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-azure-arm
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-bladecenter
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-brocade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-cisco-mds
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-cisco-ucs
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-common
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-compute
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-drac5
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-eaton-snmp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-emerson
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-eps
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-gce
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-heuristics-ping
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-hpblade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibm-powervs
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibm-vpc
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ibmblade
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ifmib
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-moonshot
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-mp
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo-ssh
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ilo2
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-intelmodular
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ipdu
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-ipmilan
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-kdump
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-kubevirt
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-lpar
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-mpath
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-nutanix-ahv
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-openstack
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-redfish
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-rhevm
    Fixed in 4.2.1-129.el8_10.20
  • fence-agents-rsa
    Fixed in 4.2.1-129.el8_10.20

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

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

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • fence-agents-aliyun
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-all
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-amt-ws
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-apc
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-apc-snmp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-aws
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-azure-arm
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-bladecenter
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-brocade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-cisco-mds
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-cisco-ucs
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-common
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-compute
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-drac5
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-eaton-snmp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-emerson
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-eps
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-gce
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-heuristics-ping
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-hpblade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibm-powervs
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibm-vpc
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ibmblade
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ifmib
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-moonshot
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-mp
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo-ssh
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ilo2
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-intelmodular
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ipdu
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-ipmilan
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-kdump
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-kubevirt
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-lpar
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-mpath
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-nutanix-ahv
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-openstack
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-redfish
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-rhevm
    Fixed in 4.10.0-98.el9_7.4
  • fence-agents-rsa
    Fixed in 4.10.0-98.el9_7.4

19 further packages in CloudLinux 9 not shown (first 40 listed).

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

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • python3-urllib3
    Fixed in 1.26.19-2.el10_1.1

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • python-urllib3
    Fixed in 1.26.12-1+deb12u3

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

Debian 13

  • python-urllib3
    Fixed in 2.3.0-3+deb13u1

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

Debian 14

  • python-urllib3
    Fixed in 2.5.0-2

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

Ubuntu 22.04 LTS

  • python-urllib3
    Fixed in 1.26.5-1~exp1ubuntu0.5

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

Ubuntu 24.04 LTS

  • python-urllib3
    Fixed in 2.0.7-1ubuntu0.4

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

Ubuntu 25.10

  • python-pip
    No fix yet
  • python-urllib3
    Fixed in 2.3.0-3ubuntu0.2

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

Ubuntu 26.10

  • python-pip
    No fix yet

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

Ubuntu Pro 18.04 LTS

  • python-pip
    No fix yet
  • python-urllib3
    No fix yet

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

Ubuntu Pro 20.04 LTS

  • python-urllib3
    Fixed in 1.25.8-2ubuntu0.4+esm3
    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 22.04 LTS

  • python-pip
    No fix yet

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

Ubuntu Pro 24.04 LTS

  • python-pip
    No fix yet

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

Ubuntu Pro 26.04 LTS

  • python-pip
    No fix yet

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.