CVE-2026-53716
Description
A flaw was found in Envoy Gateway. A remote attacker, by providing a specially crafted compressed WebAssembly (Wasm) payload through a tenant-controlled URL, can exploit a vulnerability where the system decompresses the gzip file without limiting the output size. This can lead to an uncontrolled memory allocation, causing the controller to terminate due to out-of-memory conditions. The resulting restarts can cause a persistent denial of service across multiple tenants.
Statement
RH Connectivity Link includes an affected Envoy Gateway version. Exploitation requires a tenant able to create an EnvoyExtensionPolicy referencing a reachable compressed Wasm payload, potentially causing controller OOM termination and cross-tenant control-plane disruption.
Mitigation
Restrict creation of EnvoyExtensionPolicy resources and constrain operator access to approved Wasm URLs until an updated Envoy Gateway version is available.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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