How severe is CVE-2020-2101?

CVE-2020-2101 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-2020-2101?

CVE-2020-2101 affects the following packages: org.jenkins-ci.main:jenkins-core (Maven), org.jenkins-ci.main:jenkins-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-2101?

Update org.jenkins-ci.main:jenkins-core to 2.204.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-2101 is resolved across your whole dependency graph.

How do I detect CVE-2020-2101 in my Maven dependencies?

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

How do I mitigate CVE-2020-2101 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-2020-2101 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-2101 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-2020-2101?

CVE-2020-2101 has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 72th 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-2020-2101?

CVE-2020-2101 is classified as CWE-203 (CWE-203). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2020-2101 published, and has it been updated?

CVE-2020-2101 was published on January 29, 2020 and was last updated on October 24, 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-2020-2101 — jenkins-core

MEDIUMFix: jenkinsci/jenkins@0ba3650

CVE-2020-2101 is a medium-severity (CVSS 5.3) CWE-203 vulnerability in org.jenkins-ci.main:jenkins-core. A fix is available for org.jenkins-ci.main:jenkins-core — see the affected versions and patch details below.

Non-constant time comparison of inbound TCP agent connection secret

Also known asBIT-jenkins-2020-2101GHSA-w7jr-wqw6-54xc

Published

Jan 29, 2020

Updated

Oct 24, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs72th percentile — riskier than 72% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

☕org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-core

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

Jenkins 2.218 and earlier, LTS 2.204.1 and earlier does not use a constant-time comparison validating the connection secret when an inbound TCP agent connection is initiated. This could potentially allow attackers to use statistical methods to obtain the connection secret.

Jenkins 2.219, LTS 2.204.2 now uses a constant-time comparison function for verifying connection secrets.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.jenkins-ci.main:jenkins-core`	all versions	2.204.2`org.jenkins-ci.main:jenkins-core:2.204.2`
☕Maven	`org.jenkins-ci.main:jenkins-core`	≥ 2.205&&< 2.219	2.219`org.jenkins-ci.main:jenkins-core:2.219`

Affected Products

1 product · 2 configurations

Application

jenkinsjenkins

≤ 2.218

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.jenkins-ci.main:jenkins-core to 2.204.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-2101 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 HatModerate

Product	Fixed in	Advisory
Red Hat OpenShift Container Platform 3.11	`atomic-enterprise-service-catalog-1:3.11.170-1.git.1.91db82e.el7`	RHBA-2020:0402
Red Hat OpenShift Container Platform 4.3	`jenkins-0:2.204.2.1583446818-1.el7`	RHBA-2020:0675
Red Hat OpenShift Container Platform 4.4	`openshift4/ose-aws-machine-controllers:v4.4.0-202004261927`	RHBA-2020:0581
Red Hat OpenShift Container Platform 4.5	`openshift4/ose-aws-machine-controllers:v4.5.0-202007012112.p0`	RHBA-2020:2409

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-2101 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Raw vector

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

CWE Classification

CWE-203CWE-203

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

jenkins

6.4/10

Code-Review6/10

Maintained10/10

Branch-Protection3/10

Assessed Oct 26, 2026

Timeline

Disclosed

Jan 29, 2020

Last updated

Oct 24, 2026

Identifiers

CVE-2020-2101

GHSA-w7jr-wqw6-54xc

BIT-jenkins-2020-2101

References

Advisoryopenwall.com Advisoryaccess.redhat.com · RHBA 2020:0402 Advisoryaccess.redhat.com · RHBA 2020:0675 Advisoryaccess.redhat.com · RHSA 2020:0681 Advisoryaccess.redhat.com · RHSA 2020:0683 Advisoryjenkins.io · 2020 01 29 Advisorynvd.nist.gov · CVE 2020 2101 Webgithub.com · 0ba36508187ff771bba87feaf03057496775064c Packagegithub.com · jenkins

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting jenkins-core are rated as high or higher (top: high).

CVE-2026-53436CVE-2026-53437CVE-2026-53440CVE-2026-53441CVE-2026-53439CVE-2026-53435CVE-2026-53442CVE-2026-53438

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2020-2101 — jenkins-core

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-2020-2101 in your dependencies?