CVE-2026-33540 Distribution affected by pull-through cache credential exfiltration via www-authenticate bearer realm

Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used...

CVE-2026-33540

CVE-2026-33540 affects the Distribution toolkit. In prior releases (before 3.1.0) and in pull-through cache mode, it parses WWW-Authenticate challenges to discover token auth endpoints, taking the realm URL from a bearer challenge without validating it against the upstream host. An attacker-contr...