CVE-2020-26154: url.cpp in libproxy through 0.4.15 is prone to a buffer overflow when PAC is enabled, as demonstrated by a...

Security readout for executives and security teams

Libproxy versions through 0.4.15 can overflow a buffer when automatic proxy configuration is enabled and it receives an unusually large PAC file without a Content-length header. Business urgency depends on whether systems use PAC-based proxy discovery and whether untrusted networks or services can influence the PAC file delivered to endpoints. Exposure is most likely on Linux desktops, servers, or applications using libproxy with PAC enabled. Systems not using PAC are less likely to be affected based on the CVE description. The bundle does not identify specific application consumers beyond libproxy packaging in major distributions. Treat this as a targeted patching item rather than an emergency internet-wide issue. Prioritize environments using PAC files, especially managed desktop fleets and systems on untrusted networks. Lack of KEV listing and missing CVSS reduce confidence in urgency, but buffer overflows in shared libraries deserve timely remediation. Mitigation focus: Update libproxy using your distribution’s security advisory packages.; Prioritize Debian, Fedora, and openSUSE systems referencing the listed advisories.; Inventory systems where PAC-based proxy configuration is enabled..

Prepared

Jun 5, 2026, 14:11 UTC (UTC+00:00)

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