Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2020-26137

23
FAUCET Score

CVE-2020-26137 is a CRLF injection vulnerability in urllib3 versions prior to 1.25.9, affecting products like Canonical, Debian, Oracle, and Python. An attacker can exploit this by controlling the HTTP request method and inserting CR/LF characters into putrequest(). This medium-severity vulnerability (CVSS 6.5) has a low attack complexity and can lead to partial confidentiality and integrity impacts. There is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 1.25.9CPE matchmatch criteria
cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*
16.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
18.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
20.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
9.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.5MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
2.5
CvssVersion
3.1

Exploit Intelligence

EPSS Score
2.27%
Probability of exploitation in next 30 days
EPSS Percentile
81.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0227 is in the 71st percentile among its peer group of 23,705 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (23)

3cxpatch availablevia llm_extracted
Fixed in: 5.4.2
github_advisorypatch availablevia nvd_reference
View patch
microsoftpatch availablevia msrc
Product: cm1 python-urllib3 1.25.9-2 on CBL Mariner 1.0Fixed in: 1.25.9-2
microsoftpatch availablevia msrc
Product: 16991-16820Fixed in: 1.25.9-2
oraclepatch availablevia nvd_reference
View patch
pippatch availablevia ghsa
Product: urllib3Fixed in: 1.25.9
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: python-urllib3-0:1.24.2-5.el8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenShift Container Platform 3.11Fixed in: python-urllib3-0:1.26.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat OpenShift Container Platform 4.5Fixed in: python-urllib3-0:1.26.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-python38-python-0:3.8.6-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-python38-python-psutil-0:5.6.4-5.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-python38-python-urllib3-0:1.25.7-6.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: rh-python38-python-0:3.8.6-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: python-0:2.7.5-92.el7_9
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: rh-python38-python-urllib3-0:1.25.7-6.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-python38-python-0:3.8.6-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-python38-python-psutil-0:5.6.4-5.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-python38-python-urllib3-0:1.25.7-6.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUSFixed in: rh-python38-python-psutil-0:5.6.4-5.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: python27:2.7-8040020210122160212.cdb2db54
View patch
redhatend of lifevia redhat_api
Product: Red Hat Storage 3Fixed in: python-urllib3
redhatend of lifevia redhat_api
Product: Red Hat Software CollectionsFixed in: rh-mongodb36-python-urllib3
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 13 (Queens)Fixed in: python-urllib3

Vendor Advisories (4)

3cxllm-3cx-1205af7554fe3711HIGH

Third-Party Package Updates in Splunk User Behavior Analytics (UBA) - April 2025

Apr 29, 2025
pipGHSA-wqvq-5m8c-6g24medium

CRLF injection in urllib3

Jun 18, 2021
microsoft2020-Sep/CVE-2020-26137Moderate

urllib3 before 1.25.9 allows CRLF injection if the attacker controls the HTTP request method as demonstrated by inserting CR and LF control characters in the first argument of putrequest(). NOTE: this is similar to CVE-2020-26116.

Sep 8, 2020
redhatCVE-2020-26137Moderate

python-urllib3: CRLF injection via HTTP request method

Feb 10, 2020

References

bugs.python.org / issue39603
Issue TrackingVendor Advisory
github.com / urllib3/urllib3/commit/1dd69c5c5982fae7c87a620d487c2ebf7a6b436b
PatchThird Party Advisory
github.com / urllib3/urllib3/pull/1800
PatchThird Party Advisory
lists.debian.org / debian-lts-announce/2021/06/msg00015.html
Mailing ListThird Party Advisory
lists.debian.org / debian-lts-announce/2023/10/msg00012.html
usn.ubuntu.com / 4570-1
Third Party Advisory
oracle.com / security-alerts/cpujul2022.html
PatchThird Party Advisory
oracle.com / security-alerts/cpuoct2021.html
PatchThird Party Advisory