{"cve":"CVE-2026-78422","nvd":{"published":"2026-08-31T15:17:58.910","modified":"2026-09-01T20:54:51.287","status":"Awaiting Analysis","description":"Subject::new_for_owner() in the zbus_polkit crate encodes the uid entry of a unix-process polkit subject as an unsigned 32-bit integer (D-Bus type u), whereas the org.freedesktop.PolicyKit1.Authority interface specifies a signed 32-bit integer (D-Bus type i). Because of this type mismatch, polkit silently discards the caller-supplied UID and instead determines the subject's owner itself by looking up the PID in /proc, a lookup that is inherently subject to a time-of-check/time-of-use race.\n\nConsequently, an application that passes a UID obtained from a trustworthy source — for example SO_PEERCRED Unix socket peer credentials — in order to defend against PID reuse receives no protection, and the supplied UID has no effect on the authorization decision. A local unprivileged attacker who can cause an authorized process to terminate and then win the race to have their own process assigned the same PID can be authorized under the identity of the terminated process, bypassing the polkit authorization check and performing actions the attacker is not entitled to.\n\nThis issue affects zbus_polkit before 5.1.0.","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":7.3},"cvss_v3":null,"cwes":["CWE-367","CWE-686"],"references":["https://bugzilla.suse.com/show_bug.cgi?id=1277659","https://github.com/z-galaxy/zbus_polkit/pull/101"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-78422","score":0.00125,"percentile":0.02167,"date":"2026-10-31"},"kev":null,"osv":[{"id":"RUSTSEC-2026-0278","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0278","summary":"`zbus_polkit`: authorization bypass via PID reuse","modified":"2026-09-02T09:15:02.887263895Z","packages":[{"ecosystem":"crates.io","name":"zbus_polkit","purl":"pkg:cargo/zbus_polkit","ranges":[">=0.0.0-0 <5.1.0"],"fixed":["5.1.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}