Is CVE-2026-55233 actively exploited?

No active exploitation of CVE-2026-55233 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-55233 be exploited remotely?

Yes. CVE-2026-55233 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-55233?

CVE-2026-55233 has a CVSS score of 7.5 (HIGH).

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HIGH

CVE-2026-55233

CWE-787Published: July 10, 2026· Updated: Jul 14, 2026

7.5

CVSS v3.1

EPSS:0.34%probability of exploitation in 30 daysPercentile:26.4th

Official Description

OpenResty is a high performance web platform. From 1.29.2.1 to before 1.29.2.5, an out-of-bounds write vulnerability exists in the upstream PROXY protocol v2 implementation. When OpenResty is configured to send PROXY protocol version 2 headers to upstream servers, constructing the header in the stream proxy protocol v2 patch can write beyond the bounds of the allocated buffer, causing the worker process to crash and resulting in a denial of service. Only configurations that explicitly enable PROXY protocol v2 for upstream connections are impacted. This issue is fixed in version 1.29.2.5.

NVD Source

Technical Analysis

CVE-2026-55233 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.