How severe is CVE-2023-42800?

CVE-2023-42800 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-42800 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42800?

CVE-2023-42800 primarily affects Moonlight-stream Moonlight-common-c. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-42800?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-42800 published?

CVE-2023-42800 was published on 2023-12-14 and last updated on 2026-06-17.

CVE-2023-42800

CVE-2023-42800 is a high-severity vulnerability in Moonlight-stream Moonlight-common-c with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Moonlight-stream Moonlight-common-c
Published: 2023-12-14
Last modified: 2026-06-17

Description

Moonlight-common-c contains the core GameStream client code shared between Moonlight clients. Moonlight-common-c is vulnerable to buffer overflow starting in commit 50c0a51b10ecc5b3415ea78c21d96d679e2288f9 due to unmitigated usage of unsafe C functions and improper bounds checking. A malicious game streaming server could exploit a buffer overflow vulnerability to crash a moonlight client, or achieve remote code execution (RCE) on the client (with insufficient exploit mitigations or if mitigations can be bypassed). The bug was addressed in commit 24750d4b748fefa03d09fcfd6d45056faca354e0.

Frequently asked questions

What is CVE-2023-42800?: Moonlight-common-c contains the core GameStream client code shared between Moonlight clients. Moonlight-common-c is vulnerable to buffer overflow starting in commit 50c0a51b10ecc5b3415ea78c21d96d679e2288f9 due to unmitigated usage of unsafe C functions and improper bounds checking. A malicious game streaming server could exploit a buffer overflow vulnerability to crash a moonlight client, or achieve remote code execution (RCE) on the client (with insufficient exploit mitigations or if mitigations can be bypassed). The bug was addressed in commit 24750d4b748fefa03d09fcfd6d45056faca354e0.
How severe is CVE-2023-42800?: CVE-2023-42800 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-42800 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42800?: CVE-2023-42800 primarily affects Moonlight-stream Moonlight-common-c. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-42800?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-42800 published?: CVE-2023-42800 was published on 2023-12-14 and last updated on 2026-06-17.

References

Affected products (10)

cpe:2.3:a:moonlight-stream:moonlight-common-c:*:*:*:*:*:*:*:*
cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:iphone_os:*:*
cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:tvos:*:*
cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:android:*:*
cpe:2.3:a:moonlight-stream:moonlight:0.10.22:*:*:*:*:chrome:*:*
cpe:2.3:a:moonlight-stream:moonlight_embedded:2.6.0:*:*:*:*:*:*:*
cpe:2.3:a:moonlight-stream:moonlight_xbox:*:*:*:*:*:*:*:*
cpe:2.3:a:moonlight-stream:moonlight_tv:*:*:*:*:*:*:*:*
cpe:2.3:a:moonlight-stream:moonlight_switch:*:*:*:*:*:*:*:*
cpe:2.3:a:moonlight-stream:moonlight_vita:*:*:*:*:*:*:*:*

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