AZL-113600: CVE-2026-97039 affecting package python-tensorboard 2.16.2-6
Building a malicious package that uses "#cgo pkg-config:" directives could load untrusted pkg-config ".pc" files or inject unvalidated compiler and linker flags. The pkg-config flag allowlist previously permitted "--with-path=" and "--personality=", allowed "--define-variable=" values beginning with "=" or "$" (which can rewrite paths in system ".pc" files into sysroot-prefixed "-L=" or "-L$SYSROOT" linker search paths), and allowed package arguments ending in ".pc" or containing path separators or "..", which caused pkg-config to load local ".pc" files directly from the package directory. In addition, flags returned by "pkg-config --cflags" in cgoCPPFLAGS were not checked when determining whether internal linking is safe. The go command now disallows "--with-path=", "--personality=", leading "=" or "$" characters in "--define-variable=" values, and local ".pc" paths in "#cgo pkg-config:" directives, and inspects cgoCPPFLAGS when checking internal linking compatibility.
Affected Software
Event History
Frequently Asked Questions
What would an attacker need to control to exploit this issue?
They would need to cause the Go command to build a malicious package containing #cgo pkg-config: directives. Those directives could be used to make pkg-config load attacker-controlled local .pc files or accept unvalidated compiler and linker flags.
Which pkg-config directive arguments were considered unsafe?
Unsafe forms included --with-path=, --personality=, and --define-variable= values beginning with = or $. Package arguments ending in .pc or containing path separators or .. could also cause local .pc files to be loaded from the package directory.
What additional linking check was missing?
Flags returned by pkg-config --cflags in cgoCPPFLAGS were not checked when deciding whether internal linking was safe. The updated behavior inspects cgoCPPFLAGS as part of that compatibility decision.