How severe is CVE-2020-5421?

CVE-2020-5421 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-5421?

CVE-2020-5421 affects the following packages: org.springframework:spring-framework-bom (Maven), org.springframework:spring-framework-bom (Maven), org.springframework:spring-framework-bom (Maven), org.springframework:spring-framework-bom (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-5421?

Update org.springframework:spring-framework-bom to 5.2.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-5421 is resolved across your whole dependency graph.

How do I detect CVE-2020-5421 in my Maven dependencies?

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

How do I mitigate CVE-2020-5421 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-2020-5421 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2020-5421, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-5421?

CVE-2020-5421 has an EPSS (Exploit Prediction Scoring System) score of 10.7%, placing it in the 96th 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 warrants monitoring and prompt remediation.

When was CVE-2020-5421 published, and has it been updated?

CVE-2020-5421 was published on September 19, 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-2020-5421 — spring-framework-bom

MEDIUM

CVE-2020-5421 is a medium-severity (CVSS 6.5) vulnerability in org.springframework:spring-framework-bom. 2 public exploit references exist, so weaponization risk is real. A fix is available for org.springframework:spring-framework-bom — see the affected versions and patch details below.

Improper Input Validation in Spring Framework

Also known asGHSA-rv39-3qh7-9v7w

Published

Sep 19, 2020

Updated

Jul 8, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

2 known

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

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2020-5421.

EPSS Exploitation Probability

via FIRST.org ↗

10.7%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs96th percentile — riskier than 96% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-5421 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 10–50% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

☕org.springframework:spring-framework-bom☕org.springframework:spring-framework-bom☕org.springframework:spring-framework-bom☕org.springframework:spring-framework-bom

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

In Spring Framework versions 5.2.0 - 5.2.8, 5.1.0 - 5.1.17, 5.0.0 - 5.0.18, 4.3.0 - 4.3.28, and older unsupported versions, the protections against RFD attacks from CVE-2015-5211 may be bypassed depending on the browser used through the use of a jsessionid path parameter.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.springframework:spring-framework-bom`	≥ 5.2.0&&< 5.2.9	5.2.9`org.springframework:spring-framework-bom:5.2.9`
☕Maven	`org.springframework:spring-framework-bom`	≥ 5.1.0&&< 5.1.18	5.1.18`org.springframework:spring-framework-bom:5.1.18`
☕Maven	`org.springframework:spring-framework-bom`	≥ 5.0.0&&< 5.0.19	5.0.19`org.springframework:spring-framework-bom:5.0.19`
☕Maven	`org.springframework:spring-framework-bom`	all versions	4.3.29`org.springframework:spring-framework-bom:4.3.29`

Affected Products

38 products · 77 configurations

Application

oncommand insightnetapp

all

Application

snap creator frameworknetapp

all

Application

snapcenternetapp

all

Application

commerce guided searchoracle

1 version

11.3.2

Application

communications brmoracle

2 versions

11.3.0.912.0.0.3

Application

communications design studiooracle

3 versions

7.3.47.3.57.4.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

In Spring Framework versions 5.2.0 - 5.2.8, 5.1.0 - 5.1.17, 5.0.0 - 5.0.…

github.comGithubJan 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework:spring-framework-bom, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.springframework:spring-framework-bom to 5.2.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-5421 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

This issue does not affect the version of SpringFramework (embedded in rhvm-dependencies) shipped with Red Hat Virtualization, as it does not provide support for spring-web. In Red Hat Gluster Storage 3, SpringFramework (embedded in rhvm-dependencies) was shipped as a part of Red Hat Gluster Storage Console that is…

Product	Fixed in	Advisory
Red Hat Fuse 7.9	`springframework`	RHSA-2021:3140

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-5421 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVE-2020-5421 — spring-framework-bom

Exploitation Status

No confirmed exploitation observed yet

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-2020-5421 in your dependencies?