{"id":"UBUNTU-CVE-2026-77421","details":"JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, the JLine built-in nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.","modified":"2026-09-25T06:38:23.356405007Z","published":"2026-09-24T00:00:00Z","upstream":["CVE-2026-77421"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-77421"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-77421"},{"type":"REPORT","url":"https://github.com/jline/jline3/security/advisories/GHSA-ph9c-7hw9-vhhw"},{"type":"REPORT","url":"https://github.com/jline/jline3/pull/2018"},{"type":"REPORT","url":"https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae"},{"type":"REPORT","url":"https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541"},{"type":"REPORT","url":"https://github.com/jline/jline3/pull/2012"},{"type":"REPORT","url":"https://github.com/jline/jline3/releases/tag/4.3.1"},{"type":"REPORT","url":"https://github.com/jline/jline3/releases/tag/jline-3.30.15"}],"affected":[{"package":{"name":"jline","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/jline?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libjline-java","binary_version":"1.0-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline2","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/jline2?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11-1","2.11-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libjline2-java","binary_version":"2.11-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/jline?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0-2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0-2","binary_name":"libjline-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline2","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/jline2?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11-4"],"ecosystem_specific":{"binaries":[{"binary_version":"2.11-4","binary_name":"libjline2-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/jline?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0-2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0-2","binary_name":"libjline-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline2","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/jline2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11-4","2.12.1-1","2.14.6-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjline2-java","binary_version":"2.14.6-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/jline?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libjline-java","binary_version":"1.0-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline2","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/jline2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.14.6-3"],"ecosystem_specific":{"binaries":[{"binary_version":"2.14.6-3","binary_name":"libjline2-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/jline?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0-3"],"ecosystem_specific":{"binaries":[{"binary_name":"libjline-java","binary_version":"1.0-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77421.json"}},{"package":{"name":"jline2","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/jline2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.14.6-4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