No exploitation reportedFix available

CVE-2016-1000111

Q: Is CVE-2016-1000111 actively exploited?

Active exploitation of CVE-2016-1000111 has not been confirmed. Its EPSS score was 2.8% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2016-1000111?

CVE-2016-1000111 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

No exploitation reported by the sources we read.

Published2020-03-11
Fixed in16.3.1
WeaknessCWE-425

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Twisted before 16.3.1 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect a CGI application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue.

Timeline

dates in UTC

2020-03-1120:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-1000111?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-1000111?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Twisted

Branch	Affected	Fixed in	Source
16.3	< 16.3.1	16.3.1	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Twisted to 16.3.1

Advisories and patches

twistedmatrix.comVendor Advisory
twistedmatrix.comPatch · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.15.3read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-425read 2026-10-23
FIRST EPSSEPSS score2.8 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Published: 2020-03-11
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-1000111?

Is CVE-2016-1000111 actively exploited?

Active exploitation of CVE-2016-1000111 has not been confirmed. Its EPSS score was 2.8% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-1000111?

CVE-2016-1000111 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

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