{"id":"CVE-2018-7548","aliases":["DEBIAN-CVE-2018-7548","EUVD-2018-19275","GHSA-52h6-vcv4-gr3c","MGASA-2018-0168"],"status":"published","title":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an...","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","severity":{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.02543,"percentile":0.85103,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-476"],"published":"2018-02-27T22:00:00Z","modified":"2026-10-24T10:30:55Z","fixes":[{"ecosystem":"Debian:12","package":"zsh","fixed_in":["5.5-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"zsh","fixed_in":["5.5-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"zsh","fixed_in":["5.5-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"zsh","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.5-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"zsh","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.5-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"zsh","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.5-1"}]}]},{"source":"osv","ecosystem":"Mageia:6","package":"zsh","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.3.1-1.2.mga6"}]}],"bundled":4}],"products":[{"vendor":"canonical","product":"ubuntu_linux"},{"vendor":"zsh","product":"zsh"}],"references":[{"url":"https://usn.ubuntu.com/3593-1/","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://security.gentoo.org/glsa/201805-10","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","Third Party Advisory","advisory"]},{"url":"https://sourceforge.net/p/zsh/code/ci/110b13e1090bc31ac1352b28adc2d02b6d25a102","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-7548"},{"url":"https://github.com/advisories/GHSA-52h6-vcv4-gr3c"},{"url":"https://security-tracker.debian.org/tracker/CVE-2018-7548","tags":["advisory"]},{"url":"https://advisories.mageia.org/MGASA-2018-0168.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=22741","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2018-7548","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2018-02-27T22:00:00Z","modified":"2024-08-05T06:31:04.316Z","updated_at":"2026-11-02T14:35:10.313768Z"}],"euvd":[{"id":"EUVD-2018-19275","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2018-02-27T22:00:00Z","modified":"2024-08-05T06:31:04Z","updated_at":"2026-11-03T02:40:05.625439Z"}],"ghsa":[{"id":"GHSA-52h6-vcv4-gr3c","title":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an...","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2022-05-14T01:28:46Z","modified":"2023-02-02T05:03:49Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:51:43.477916Z"}],"nvd":[{"id":"CVE-2018-7548","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2018-02-27T22:29:00.59Z","modified":"2026-06-17T02:03:21.063Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:04:23.783914Z"}],"osv":[{"id":"CVE-2018-7548","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2018-02-27T22:29:00.59Z","modified":"2026-10-24T10:30:55.881744094Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:09.74357Z"},{"id":"DEBIAN-CVE-2018-7548","description":"In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.","status":"published","published":"2018-02-27T22:29:00.59Z","modified":"2026-10-23T18:03:58.469270746Z","cvss":[{"version":"3.0","score":9.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:31.170944Z"},{"id":"MGASA-2018-0168","title":"Updated zsh packages fix security vulnerabilities","description":"Zsh has been updated to fix 4 security issues.\n\nIn builtin.c in zsh before 5.4, when sh compatibility mode is used, there is a \nNULL pointer dereference during processing of the cd command with no argument if \nHOME is not set. (CVE-2017-18205)\n\nIn utils.c in zsh before 5.4, symlink expansion had a buffer overflow. \n(CVE-2017-18206)\n\nIn subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using \n${(PA)...} on an empty array result.(CVE-2018-7548)\n\nIn params.c in zsh through 5.4.2, there is a crash during a copy of an empty \nhash table, as demonstrated by typeset -p. (CVE-2018-7549)\n","status":"published","published":"2018-03-14T16:21:20Z","modified":"2026-04-16T06:25:54.5642248Z","updated_at":"2026-11-02T15:49:40.442238Z"}]}}