CVE-2026-55233

Name of the Vulnerable Software and Affected Versions OpenResty versions 1.29.2.1 through 1.29.2.4

Description An out-of-bounds write occurs in the upstream PROXY protocol v2 implementation. When the platform is configured to send PROXY protocol version 2 headers to upstream servers, the process of constructing the header in the stream proxy protocol v2 patch can write beyond the allocated buffer. This leads to a worker process crash and a subsequent denial of service. This issue only affects configurations that explicitly enable PROXY protocol v2 for upstream connections.

Recommendations Update to version 1.29.2.5. As a temporary mitigation, disable the use of PROXY protocol v2 for upstream connections.