How severe is CVE-2023-4043?

CVE-2023-4043 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-4043?

CVE-2023-4043 affects the following packages: org.eclipse.parsson:project (Maven), org.eclipse.parsson:project (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-4043?

Update org.eclipse.parsson:project to 1.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-4043 is resolved across your whole dependency graph.

How do I detect CVE-2023-4043 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.parsson:project. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-4043 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-2023-4043?

O3 pinpoints whether CVE-2023-4043 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-4043 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-4043, 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-2023-4043?

CVE-2023-4043 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 51th 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-2023-4043 published, and has it been updated?

CVE-2023-4043 was published on November 3, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-4043: Eclipse Parsson Denial of Service vulnerability…

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk51th percentile+0.61%

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.

Blast Radius

2 pkgs affected

☕org.eclipse.parsson:project☕org.eclipse.parsson:project

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 Eclipse Parsson before versions 1.1.4 and 1.0.5, Parsing JSON from untrusted sources can lead malicious actors to exploit the fact that the built-in support for parsing numbers with large scale in Java has a number of edge cases where the input text of a number can lead to much larger processing time than one would expect.

To mitigate the risk, parsson put in place a size limit for the numbers as well as their scale.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.eclipse.parsson:project`	≥ 1.1.0&&< 1.1.4	1.1.4
☕Maven	`org.eclipse.parsson:project`	all versions	1.0.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.parsson:project. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.eclipse.parsson:project to 1.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-4043 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 pinpoints whether CVE-2023-4043 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-4043. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In Eclipse Parsson before versions 1.1.4 and 1.0.5, Parsing JSON from untrusted sources can lead malicious actors to exploit the fact that the built-in support for parsing numbers with large scale in Java has a number of edge cases where the input text of a number can lead to much larger processing time than one would expect. To mitigate the risk, parsson put in place a size limit for the numbers as well as their scale.

O3 Security · Impact-Aware SCA

Is CVE-2023-4043 in your dependencies?

O3 detects CVE-2023-4043 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2023-4043