CVE-2021-31806: An issue was discovered in Squid before 4.15 and 5.x before 5.0.6.

Security readout for executives and security teams

CVE-2021-31806 is a denial-of-service flaw in Squid proxy. A memory-management bug in HTTP Range request handling can disrupt the proxy for all clients that depend on it, creating an availability risk rather than a confirmed data-theft risk. Exposure is likely where organizations run Squid as an explicit, reverse, or caching proxy, including vendor appliances bundling Squid. Internet-reachable proxies carry higher business impact. Treat as a timely availability fix for shared proxy infrastructure. It is not documented here as actively exploited, but a proxy outage can interrupt many users or services at once. Mitigation focus: Upgrade Squid to 4.15, 5.0.6, or later vendor-supported builds.; Apply Debian, Fedora, NetApp, or other vendor security updates where Squid is bundled.; Prioritize proxies serving production, remote access, or shared outbound traffic..

Prepared

Jun 3, 2026, 02:27 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.