{"id":"CVE-2020-26137","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-26137","generatedAt":"2026-10-27T20:22:06.997Z","title":"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().","description":"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.","published":"2020-09-30T18:15:27.000Z","lastModified":"2026-06-17T03:07:40.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},"cwe":["CWE-74"],"affected":["python/urllib3","canonical/ubuntu linux","debian/debian linux","oracle/communications cloud native core network function cloud native environment","oracle/zfs storage appliance kit"],"epss":{"score":0.02269,"percentile":0.82927,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (2.27%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://bugs.python.org/issue39603","tags":["Issue Tracking","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/urllib3/urllib3/commit/1dd69c5c5982fae7c87a620d487c2ebf7a6b436b","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/urllib3/urllib3/pull/1800","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00012.html","source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/4570-1/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.oracle.com/security-alerts/cpujul2022.html","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://bugs.python.org/issue39603","tags":["Issue Tracking","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/urllib3/urllib3/commit/1dd69c5c5982fae7c87a620d487c2ebf7a6b436b","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/urllib3/urllib3/pull/1800","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00012.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4570-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpujul2022.html","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-26137","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}