How severe is CVE-2020-13956?

CVE-2020-13956 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-2020-13956?

CVE-2020-13956 affects the following packages: org.apache.httpcomponents:httpclient (Maven), org.apache.httpcomponents:httpclient (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-13956?

Update org.apache.httpcomponents:httpclient to 4.5.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13956 is resolved across your whole dependency graph.

How do I detect CVE-2020-13956 in my Maven dependencies?

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

How do I mitigate CVE-2020-13956 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.

How does O3 Security protect against CVE-2020-13956?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-13956 can be triaged on real exposure rather than presence alone.

Is CVE-2020-13956 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-13956 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-2020-13956?

CVE-2020-13956 has an EPSS (Exploit Prediction Scoring System) score of 9.0%, placing it in the 95th 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.

When was CVE-2020-13956 published, and has it been updated?

CVE-2020-13956 was published on December 2, 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.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2020-13956 — httpclient

MEDIUM

CVE-2020-13956 is a medium-severity (CVSS 5.3) vulnerability in org.apache.httpcomponents:httpclient. A fix is available for org.apache.httpcomponents:httpclient — see the affected versions and patch details below.

Cross-site scripting in Apache HttpClient

Also known asGHSA-7r82-7xv7-xcpj

Published

Dec 2, 2020

Updated

Jul 8, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

9.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2020-13956 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

2 pkgs affected

☕org.apache.httpcomponents:httpclient☕org.apache.httpcomponents:httpclient

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

Description

Apache HttpClient versions prior to version 4.5.13 and 5.0.3 can misinterpret malformed authority component in request URIs passed to the library as java.net.URI object and pick the wrong target host for request execution.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.httpcomponents:httpclient`	all versions	4.5.13`org.apache.httpcomponents:httpclient:4.5.13`
☕Maven	`org.apache.httpcomponents:httpclient`	≥ 5.0.0&&< 5.0.3	5.0.3`org.apache.httpcomponents:httpclient:5.0.3`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.httpcomponents:httpclient, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.httpcomponents:httpclient to 4.5.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13956 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-13956 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2020-13956. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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 HatModerate

In OpenShift Container Platform (OCP) the affected components are behind OpenShift OAuth authentication. This restricts access to the vulnerable httpclient library to authenticated users only. Additionally the vulnerable httpclient library is not used directly in OCP components, therefore the impact by this…

Product	Fixed in	Advisory
Red Hat AMQ 7.9.0	`httpclient`	RHSA-2021:3700
Red Hat build of Quarkus 1.7.6	`httpclient`	RHSA-2021:0084
Red Hat Enterprise Linux 8	`maven:3.6-8060020211119162118.5dbfe8be`	RHSA-2022:1860
Red Hat Enterprise Linux 8	`maven:3.5-8060020211117110044.c0229ad2`	RHSA-2022:1861
Red Hat Fuse 7.12	see advisory	RHSA-2023:3954
Red Hat Fuse 7.9	`httpclient`	RHSA-2021:3140
Red Hat Integration - Camel K - Tech-Preview 3	`httpclient`	RHSA-2021:0811
Red Hat JBoss Enterprise Application Platform 7	`httpclient`	RHSA-2021:0250

UbuntuMEDIUM

USN-5239-1Ubuntu

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-13956 in your dependencies?

O3 Security finds CVE-2020-13956 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

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