Vulnerability · Published May 22, 2026 · Assigned by GitHub_M

CVE-2026-32253Sunshine: Authentication bypass via improper client certificate validation

Critical 9.8

In plain English

A critical-severity improper authentication in Sunshine from LizardByte. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.3%top 78.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
LizardByte	Sunshine	< 2026.516.143833

Weakness: CWE-287, CWE-295 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/LizardByte/Sunshine/security/advisories/GHSA-ph75-mgxh-mv57 x_refsource_CONFIRM
https://github.com/LizardByte/Sunshine/releases/tag/v2026.516.143833 x_refsource_MISC