CVE-2020-26137: 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.

Overview

Severity
Medium (CVSS 6.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Exploit Status
Not Exploited
Patch Tuesday
2020-Sep
Released
2020-12-21
EPSS Score
0.28% (percentile: 51.2%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Affected Products (2)

Other

  • 16991-16820
  • 19849-17086

Revision History

  • 2020-12-21: Information published.