How severe is CVE-2021-23900?

CVE-2021-23900 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-23900?

CVE-2021-23900 affects the following packages: com.mikesamuel:json-sanitizer (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-23900?

Update com.mikesamuel:json-sanitizer to 1.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23900 is resolved across your whole dependency graph.

How do I detect CVE-2021-23900 in my Maven dependencies?

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

How do I mitigate CVE-2021-23900 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2021-23900 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-23900 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-2021-23900?

CVE-2021-23900 has an EPSS (Exploit Prediction Scoring System) score of 2.1%, placing it in the 81th 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-2021-23900 published, and has it been updated?

CVE-2021-23900 was published on January 13, 2021 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

HIGH severity

CVE-2021-23900 — json-sanitizer

HIGHFix: OWASP/json-sanitizer@a37f594

CVE-2021-23900 is a high-severity (CVSS 7.5) vulnerability in com.mikesamuel:json-sanitizer. A fix is available for com.mikesamuel:json-sanitizer — see the affected versions and patch details below.

Uncaught Exception leading to Denial of Service in json-sanitizer

Also known asGHSA-8rf5-92jh-3vc9

Published

Jan 13, 2021

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs81th percentile — riskier than 81% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-23900 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.mikesamuel:json-sanitizer

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

OWASP json-sanitizer before 1.2.2 can output invalid JSON or throw an undeclared exception for crafted input. This may lead to denial of service if the application is not prepared to handle these situations.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.mikesamuel:json-sanitizer`	all versions	1.2.2`com.mikesamuel:json-sanitizer:1.2.2`

Affected Products

1 product · 1 configurations

Application

json-sanitizerowasp

< 1.2.2

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.mikesamuel:json-sanitizer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.mikesamuel:json-sanitizer to 1.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23900 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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