How severe is CVE-2023-43208?

CVE-2023-43208 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-43208?

Affected package information for CVE-2023-43208 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2023-43208?

Upgrade the affected component to the fixed release for CVE-2023-43208, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2023-43208 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2023-43208 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2023-43208 actively exploited in the wild?

Yes. There are 10 known exploit references for CVE-2023-43208, including 5 in-the-wild exploitations 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-2023-43208?

CVE-2023-43208 has an EPSS (Exploit Prediction Scoring System) score of 82.7%, placing it in the 100th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2023-43208 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2023-43208 (NextGen Healthcare Mirth Connect Deserialization of Untrusted Data Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2024-05-20. CISA required all US federal civilian agencies to remediate this vulnerability by 2024-06-10. The required action was: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2023-43208?

CVE-2023-43208 is classified as OS Command Injection (CWE-78), Deserialization of Untrusted Data (CWE-502). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2023-43208?

A Nuclei detection template exists for CVE-2023-43208, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2023-43208 published, and has it been updated?

CVE-2023-43208 was published on October 26, 2023 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

CRITICAL severity

CVE-2023-43208 — connect

CRITICAL

CVE-2023-43208 is a critical-severity (CVSS 9.8) OS Command Injection vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2024-05-20) and has been used in ransomware campaigns — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.

Published

Oct 26, 2023

Updated

Oct 20, 2026

Affected

1 product

Patched

See advisory

Exploits

10 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2024-05-20 — including use in ransomware campaigns. Federal agencies were required to remediate by 2024-06-10.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-43208.

EPSS Exploitation Probability

via FIRST.org ↗

82.7%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2023-43208 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.

Description

NextGen Healthcare Mirth Connect before version 4.4.1 is vulnerable to unauthenticated remote code execution. Note that this vulnerability is caused by the incomplete patch of CVE-2023-37679.

Affected Products

1 product · 1 configurations

Application

mirth connectnextgen

< 4.4.1

range

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.