{"id":"CVE-2026-54778","aliases":["EUVD-2026-42465","GHSA-q6v9-43v5-jv9q"],"status":"published","title":"CoreWCF: UnixDomainSocket Non-Reentrant POSIX Identity Resolution","description":"CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF UnixDomainSocket POSIX peer identity resolution uses non-reentrant getpwuid and getgrgid calls, allowing concurrent connections to attribute one connection's identity to another or crash the host process under contention. This issue is fixed in versions 1.8.1 and 1.9.1.","severity":{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00127,"percentile":0.02442,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-362","CWE-825"],"published":"2026-06-19T20:46:58Z","modified":"2026-10-28T02:30:44Z","fixes":[{"ecosystem":"NuGet","package":"CoreWCF.UnixDomainSocket","fixed_in":["1.8.1","1.9.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"CoreWCF.UnixDomainSocket","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.1"}]}]},{"source":"ghsa","ecosystem":"NuGet","package":"CoreWCF.UnixDomainSocket","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.9.0"},{"fixed":"1.9.1"}]}]},{"source":"osv","ecosystem":"NuGet","package":"CoreWCF.UnixDomainSocket","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.1"}]}],"versions":["1.5.0","1.5.0-preview1","1.5.1","1.5.2","1.6.0","1.7.0","1.8.0"]},{"source":"osv","ecosystem":"NuGet","package":"CoreWCF.UnixDomainSocket","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.9.0"},{"fixed":"1.9.1"}]}],"versions":["1.9.0"]}],"products":[{"vendor":"corewcf","product":"corewcf"}],"references":[{"url":"https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-q6v9-43v5-jv9q","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/a3d95ea4627b818995e92c7def4c016164cacfce","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/b0acb105589b455a095ea5ff49f5191e4eeff791","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/commit/b4867547c94bb088568935d581a55dda18a621e1","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/advisories/GHSA-q6v9-43v5-jv9q"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54778.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54778","tags":["advisory"]},{"url":"https://github.com/CoreWCF/CoreWCF","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-54778","title":"CoreWCF: UnixDomainSocket Non-Reentrant POSIX Identity Resolution","description":"CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF UnixDomainSocket POSIX peer identity resolution uses non-reentrant getpwuid and getgrgid calls, allowing concurrent connections to attribute one connection's identity to another or crash the host process under contention. This issue is fixed in versions 1.8.1 and 1.9.1.","status":"published","published":"2026-07-08T22:11:55.49Z","modified":"2026-07-09T13:23:29.922Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-362","CWE-825"],"updated_at":"2026-11-02T13:38:09.774038Z"}],"euvd":[{"id":"EUVD-2026-42465","description":"CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF UnixDomainSocket POSIX peer identity resolution uses non-reentrant getpwuid and getgrgid calls, allowing concurrent connections to attribute one connection's identity to another or crash the host process under contention. This issue is fixed in versions 1.8.1 and 1.9.1.","status":"published","published":"2026-07-08T22:11:55Z","modified":"2026-07-09T13:23:29Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-02T18:20:04.523855Z"}],"ghsa":[{"id":"GHSA-q6v9-43v5-jv9q","title":"CoreWCF: UnixDomainSocket Non-Reentrant POSIX Identity Resolution","description":"### Impact\nRace condition in POSIX peer identity resolution may attribute one connection’s identity to another (getpwuid/getgrgid non-reentrant) and may crash the host process under contention.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nRestrict UDS filesystem permissions so that only trusted local users can connect to the socket path. The race still exists but the attacker pool is constrained.","status":"published","published":"2026-06-19T20:46:58Z","modified":"2026-06-19T20:46:59Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium"}],"cwes":["CWE-362","CWE-825"],"updated_at":"2026-11-02T14:40:31.656952Z"}],"nvd":[{"id":"CVE-2026-54778","description":"CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF UnixDomainSocket POSIX peer identity resolution uses non-reentrant getpwuid and getgrgid calls, allowing concurrent connections to attribute one connection's identity to another or crash the host process under contention. This issue is fixed in versions 1.8.1 and 1.9.1.","status":"published","published":"2026-07-08T23:16:55.493Z","modified":"2026-07-09T16:29:14.203Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-362","CWE-825"],"updated_at":"2026-11-02T14:12:28.4135Z"}],"osv":[{"id":"CVE-2026-54778","title":"CoreWCF: UnixDomainSocket Non-Reentrant POSIX Identity Resolution","description":"CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF UnixDomainSocket POSIX peer identity resolution uses non-reentrant getpwuid and getgrgid calls, allowing concurrent connections to attribute one connection's identity to another or crash the host process under contention. This issue is fixed in versions 1.8.1 and 1.9.1.","status":"published","published":"2026-07-08T22:11:55.49Z","modified":"2026-10-28T02:30:44.988270861Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium"}],"cwes":["CWE-362","CWE-825"],"updated_at":"2026-11-02T15:45:10.818486Z"},{"id":"GHSA-q6v9-43v5-jv9q","title":"CoreWCF: UnixDomainSocket Non-Reentrant POSIX Identity Resolution","description":"### Impact\nRace condition in POSIX peer identity resolution may attribute one connection’s identity to another (getpwuid/getgrgid non-reentrant) and may crash the host process under contention.\n\n### Patches\nFixed in CoreWCF v1.8.1 and v1.9.1\n\n### Workarounds\nRestrict UDS filesystem permissions so that only trusted local users can connect to the socket path. The race still exists but the attacker pool is constrained.","status":"published","published":"2026-06-19T20:46:58Z","modified":"2026-06-19T21:11:30.07893Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","level":"medium"}],"cwes":["CWE-362","CWE-825"],"updated_at":"2026-11-02T15:46:54.055966Z"}]}}