How severe is CVE-2016-1000111?

CVE-2016-1000111 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2016-1000111?

CVE-2016-1000111 affects the following packages: twisted (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2016-1000111?

Update twisted to 16.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-1000111 is resolved across your whole dependency graph.

How do I detect CVE-2016-1000111 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for twisted, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2016-1000111 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2016-1000111 actively exploited in the wild?

No public exploit code has been indexed for CVE-2016-1000111 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

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

CVE-2016-1000111 has an EPSS (Exploit Prediction Scoring System) score of 2.8%, placing it in the 86th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2016-1000111?

CVE-2016-1000111 is classified as CWE-425 (CWE-425). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2016-1000111 published, and has it been updated?

CVE-2016-1000111 was published on March 11, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2016-1000111 — twisted

MEDIUM

CVE-2016-1000111 is a medium-severity (CVSS 5.3) CWE-425 vulnerability in twisted. A fix is available for twisted — see the affected versions and patch details below.

Forced Browsing in Twisted

Also known asGHSA-3gqj-cmxr-p4x2PYSEC-2020-214

Published

Mar 11, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs86th percentile — riskier than 86% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2016-1000111 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍twisted

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`twisted`	all versions	16.3.1`pip install --upgrade 'twisted==16.3.1'`

Affected Products

1 product · 1 configurations

Application

twistedtwisted

< 16.3.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for twisted, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update twisted to 16.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-1000111 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This issue affects the versions of python-twisted as shipped with Red Hat Satellite 6.x. However due to the manner in which python-twisted is used exploitation of this issue by an attacker would require significant access to the server, or be able to modify requests from other users via additional vulnerabilities. A…

Product	Fixed in	Advisory
Red Hat Enterprise Linux 6	`python-twisted-web-0:8.2.0-5.el6_8`	RHSA-2016:1978
Red Hat Satellite 6.2 for RHEL 6	`candlepin-0:0.9.54.26-1.el6`	RHSA-2018:0273

UbuntuMEDIUM

USN-3585-1Ubuntu

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2016-1000111 in your dependencies?

Find it across PyPI, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Raw vector

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

CWE Classification

CWE-425CWE-425

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Mar 11, 2020

Last updated

Jul 8, 2026

Identifiers

CVE-2016-1000111

GHSA-3gqj-cmxr-p4x2

PYSEC-2020-214

References

Advisoryoracle.com Advisorytwistedmatrix.com Advisoryopenwall.com Advisorynvd.nist.gov Fixtwistedmatrix.com Webgithub.com Packagegithub.com

Related vulnerabilities

Also affects twisted

This CVE is medium severity; 6 of 6 other CVEs affecting twisted are rated as high or higher (top: critical).

CVE-2024-41671CVE-2024-41810GHSA-8r99-h8j2-rw64GHSA-32gv-6cf3-wcmqCVE-2022-21716CVE-2019-12387

Same weakness: CWE-425

This CVE is medium severity, in line with the other 2 CVEs with CWE-425.

CVE-2026-11986CVE-2026-8205Browse all CWE-425

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 8, 2026

CVE-2016-1000111 — twisted

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2016-1000111 in your dependencies?