How severe is CVE-2026-32253?

CVE-2026-32253 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-32253 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-32253?

CVE-2026-32253 affects Lizardbyte Sunshine. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-32253?

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

Does CVE-2026-32253 have an EU (EUVD) identifier?

Yes. CVE-2026-32253 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31469.

When was CVE-2026-32253 published?

CVE-2026-32253 was published on 2026-05-22 and last updated on 2026-06-17.

CVE-2026-32253

CVE-2026-32253 is a critical-severity vulnerability in Lizardbyte Sunshine with a CVSS 3.x base score of 9.8. 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31469
Weakness: CWE-287
Affected product: Lizardbyte Sunshine
Published: 2026-05-22
Last modified: 2026-06-17

Description

Sunshine is a self-hosted game stream host for Moonlight. In versions prior to 2026.516.143833, the client-certificate authentication can be bypassed because of how OpenSSL verification results are handled. In src/crypto.cpp, the custom verify callback treats X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, X509_V_ERR_CERT_NOT_YET_VALID, and X509_V_ERR_CERT_HAS_EXPIRED as success. This can allow an untrusted certificate to pass authentication and access protected HTTPS endpoints. This issue has been fixed in version 2026.516.143833.

Frequently asked questions

What is CVE-2026-32253?: Sunshine is a self-hosted game stream host for Moonlight. In versions prior to 2026.516.143833, the client-certificate authentication can be bypassed because of how OpenSSL verification results are handled. In src/crypto.cpp, the custom verify callback treats X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, X509_V_ERR_CERT_NOT_YET_VALID, and X509_V_ERR_CERT_HAS_EXPIRED as success. This can allow an untrusted certificate to pass authentication and access protected HTTPS endpoints. This issue has been fixed in version 2026.516.143833.
How severe is CVE-2026-32253?: CVE-2026-32253 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-32253 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-32253?: CVE-2026-32253 affects Lizardbyte Sunshine. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-32253?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-32253 have an EU (EUVD) identifier?: Yes. CVE-2026-32253 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31469.
When was CVE-2026-32253 published?: CVE-2026-32253 was published on 2026-05-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:lizardbyte:sunshine:*:*:*:*:*:*:*:*

More vulnerabilities in Lizardbyte Sunshine

CVE-2025-53095 — Critical (CVSS 9.6): Sunshine is a self-hosted game stream host for Moonlight. Prior to version 2025.628.4510, the web UI of Sunshine lacks…
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CVE-2024-31220 — High (CVSS 7.3): Sunshine is a self-hosted game stream host for Moonlight. Starting in version 0.16.0 and prior to version 0.18.0, an…
CVE-2025-54081 — Medium (CVSS 6.7): Sunshine is a self-hosted game stream host for Moonlight. Prior to version 2025.923.33222, the Windows service…

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