CVE-2020-26116http.client in Python 3.x before 3.5.10, 3.6.x before 3.6.12, 3.7.x before 3.7.9, and 3.8.x before 3.8.5 allows CRLF injection if the attacker controls the HTTP request method, as demonstrated by ins…
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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 10 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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http.client in Python 3.x before 3.5.10, 3.6.x before 3.6.12, 3.7.x before 3.7.9, and 3.8.x before 3.8.5 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 HTTPConnection.request.
- CVSS
- 7.2 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mitre
- NVD analysis
- Modified
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
python python python:python | from 3.0.0 before 3.5.10; from 3.6.0 before 3.6.12; from 3.7.0 before 3.7.9; from 3.8.0 before 3.8.5 | NVD |
fedoraproject fedora fedoraproject:fedora | 31; 32; 33 | NVD |
canonical ubuntu_linux canonical:ubuntu_linux | 12.04; 14.04; 16.04; 18.04 | NVD |
netapp solidfire netapp:solidfire | all versions | NVD |
netapp hci_storage_node netapp:hci_storage_node | all versions | NVD |
debian debian_linux debian:debian_linux | 9.0 | NVD |
oracle zfs_storage_appliance_kit oracle:zfs_storage_appliance_kit | 8.8 | NVD |
opensuse leap opensuse:leap | 15.1 | NVD |
References
- https://python-security.readthedocs.io/vuln/http-header-injection-method.htmlpatch, third-party-advisory
- https://bugs.python.org/issue39603exploit, issue-tracking, patch, vendor-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BW4GCLQISJCOEGQNIMVUZDQMIY6RR6CC/vendor-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JWMAVY4T4257AZHTF2RZJKNJNSJFY24O/vendor-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OXI72HIHMXCQFWTULUXDG7VDA2BCYL4Y/vendor-advisory
- https://usn.ubuntu.com/4581-1/vendor-advisory, third-party-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HDQ2THWU4GPV4Y5H5WW5PFMSWXL2CRFD/vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00027.htmlvendor-advisory, mailing-list, third-party-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QOX7DGMMWWL6POCRYGAUCISOLR2IG3XV/vendor-advisory
- https://lists.debian.org/debian-lts-announce/2020/11/msg00032.htmlmailing-list, third-party-advisory
- https://security.gentoo.org/glsa/202101-18vendor-advisory, third-party-advisory
- https://www.oracle.com/security-alerts/cpuoct2021.htmlpatch, third-party-advisory
- https://security.netapp.com/advisory/ntap-20201023-0001/third-party-advisory
- https://lists.debian.org/debian-lts-announce/2023/05/msg00024.htmlmailing-list
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.