{"id":"CVE-2006-0459","aliases":["BELL-CVE-2006-0459","DEBIAN-CVE-2006-0459","DSA-1020-1","EUVD-2006-0466","GHSA-c6v8-67cp-6v4p"],"status":"published","title":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33...","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","severity":{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.04708,"percentile":0.91882,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-119"],"published":"2006-03-28T00:00:00Z","modified":"2026-10-22T23:47:20Z","fixes":[{"ecosystem":"Debian:12","package":"flex","fixed_in":["2.5.33-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"flex","fixed_in":["2.5.33-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"flex","fixed_in":["2.5.33-1"],"sources":["osv"]},{"ecosystem":"Debian:3.1","package":"flex","fixed_in":["2.5.31-31sarge1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.33-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.33-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.33-1"}]}]},{"source":"osv","ecosystem":"Debian:3.1","package":"flex","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.31-31sarge1"}]}],"versions":["2.5.31-31"]}],"products":[{"vendor":"westes","product":"flex"}],"references":[{"url":"http://prdownloads.sourceforge.net/flex/flex-2.5.33.tar.bz2?download","tags":["x_refsource_CONFIRM","x_transferred","Product","web"]},{"url":"http://www.osvdb.org/23440","tags":["vdb-entry","x_refsource_OSVDB","x_transferred","Broken Link","Patch","fix","web"]},{"url":"http://www.us.debian.org/security/2006/dsa-1020","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred","Patch","Vendor Advisory","advisory","fix"]},{"url":"http://www.vupen.com/english/advisories/2006/0770","tags":["vdb-entry","x_refsource_VUPEN","x_transferred","Broken Link","URL Repurposed","advisory"]},{"url":"http://secunia.com/advisories/19071","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Patch","Vendor Advisory","advisory","fix"]},{"url":"http://www.securityfocus.com/bid/16896","tags":["vdb-entry","x_refsource_BID","x_transferred","Patch","Third Party Advisory","VDB Entry","advisory","fix"]},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/24995","tags":["vdb-entry","x_refsource_XF","x_transferred","VDB Entry","advisory"]},{"url":"http://www.gentoo.org/security/en/glsa/glsa-200603-07.xml","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","Third Party Advisory","advisory"]},{"url":"http://secunia.com/advisories/19228","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Vendor Advisory","advisory"]},{"url":"http://secunia.com/advisories/19424","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Patch","Vendor Advisory","advisory","fix"]},{"url":"http://securityreason.com/securityalert/570","tags":["third-party-advisory","x_refsource_SREASON","x_transferred","Third Party Advisory","advisory"]},{"url":"http://secunia.com/advisories/19126","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Vendor Advisory","advisory"]},{"url":"https://usn.ubuntu.com/260-1/","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred","Third Party Advisory","advisory"]},{"url":"http://sourceforge.net/mailarchive/forum.php?thread_name=20060223020346.GA11231%40tabitha.home.tldz.org\u0026forum_name=flex-announce","tags":["mailing-list","x_refsource_MLIST","x_transferred","Release Notes","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2006-0459"},{"url":"https://usn.ubuntu.com/260-1"},{"url":"https://github.com/advisories/GHSA-c6v8-67cp-6v4p"},{"url":"https://docs.bell-sw.com/security/cves/CVE-2006-0459","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2006-0459","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2006-0459","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2006-03-29T23:00:00Z","modified":"2024-08-07T16:34:14.696Z","updated_at":"2026-11-02T14:33:52.569914Z"}],"euvd":[{"id":"EUVD-2006-0466","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2006-03-29T23:00:00Z","modified":"2024-08-07T16:34:14Z","updated_at":"2026-11-03T01:16:09.484912Z"}],"ghsa":[{"id":"GHSA-c6v8-67cp-6v4p","title":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33...","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2022-05-01T06:40:03Z","modified":"2025-04-03T04:30:16Z","cwes":["CWE-119"],"updated_at":"2026-11-02T15:00:45.528888Z"}],"nvd":[{"id":"CVE-2006-0459","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2006-03-29T23:02:00Z","modified":"2026-06-16T22:20:38.97Z","cvss":[{"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-119"],"updated_at":"2026-11-02T14:01:01.776256Z"}],"osv":[{"id":"BELL-CVE-2006-0459","title":"CVE-2006-0459 does not affect BellSoft software","status":"withdrawn","published":"2006-03-29T23:02:00Z","modified":"2026-01-28T07:21:42.403511Z","cvss":[{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high"}],"updated_at":"2026-11-02T15:28:12.886815Z"},{"id":"CVE-2006-0459","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2006-03-29T23:02:00Z","modified":"2026-04-10T03:38:20.758572Z","updated_at":"2026-11-02T15:43:56.581247Z"},{"id":"DEBIAN-CVE-2006-0459","description":"flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.","status":"published","published":"2006-03-29T23:02:00Z","modified":"2026-10-22T23:47:20.911154279Z","updated_at":"2026-11-02T15:45:22.831407Z"},{"id":"DSA-1020-1","title":"flex - buffer overflow","status":"published","published":"2006-03-28T00:00:00Z","modified":"2026-03-09T01:00:43.388696Z","updated_at":"2026-11-02T15:46:13.900249Z"}]}}