How severe is CVE-2020-28923?

CVE-2020-28923 has a CVSS score of 2.7/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-28923?

CVE-2020-28923 affects the following packages: com.typesafe.play:play (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-28923?

Update com.typesafe.play:play to 2.8.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28923 is resolved across your whole dependency graph.

How do I detect CVE-2020-28923 in my Maven dependencies?

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

How do I mitigate CVE-2020-28923 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-2020-28923 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-28923 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-2020-28923?

CVE-2020-28923 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 61th 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-2020-28923 published, and has it been updated?

CVE-2020-28923 was published on December 3, 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

LOW severity

CVE-2020-28923 — play

LOW

CVE-2020-28923 is a low-severity (CVSS 2.7) vulnerability in com.typesafe.play:play. A fix is available for com.typesafe.play:play — see the affected versions and patch details below.

Data Amplification in Play Framework

Also known asGHSA-v9mf-jgq3-c28h

Published

Dec 3, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs61th percentile — riskier than 61% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-28923 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 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

☕com.typesafe.play:play

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

An issue was discovered in Play Framework 2.8.0 through 2.8.4. Carefully crafted JSON payloads sent as a form field lead to Data Amplification. This affects users migrating from a Play version prior to 2.8.0 that used the Play Java API to serialize classes with protected or private fields to JSON.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.typesafe.play:play`	≥ 2.8.0&&< 2.8.5	2.8.5`com.typesafe.play:play:2.8.5`

Affected Products

1 product · 1 configurations

Application

play frameworklightbend

≥ 2.8.0 && ≤ 2.8.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.typesafe.play:play, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.typesafe.play:play to 2.8.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28923 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.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-28923 in your dependencies?

Find it across Maven, including transitive dependencies.

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