CVE-2019-12525: An issue was discovered in Squid 3.3.9 through 3.5.28 and 4.x through 4.7.

Security readout for executives and security teams

CVE-2019-12525 affects Squid proxy deployments using Digest authentication. A malformed Proxy-Authorization header can trigger unsafe memory copying during token parsing. The provided sources do not state business impact, CVSS severity, or active exploitation, but affected internet-facing or shared proxies should be treated as operationally important. Exposure is limited to affected Squid versions configured to use Digest authentication and receive Proxy-Authorization headers. Proxies not using Digest authentication are less likely to be reachable through the described code path, based on the provided description. Patch during the next security maintenance window, sooner for internet-facing or widely used proxy infrastructure. The lack of CVSS and exploitation evidence lowers certainty, but proxy authentication parsing bugs can affect availability and trust boundaries. Mitigation focus: Upgrade affected Squid packages using vendor security advisories for your distribution.; Apply the upstream Squid changeset if maintaining a custom build.; Review Squid Digest authentication use and follow vendor guidance for safe configuration..

Prepared

Jun 6, 2026, 20:22 UTC (UTC+00:00)

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