{"id":"CVE-2026-77421","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77421","generatedAt":"2026-10-27T23:57:02.786Z","title":"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.","description":"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.","published":"2026-09-23T19:19:16.000Z","lastModified":"2026-09-30T16:44:40.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-1333"],"affected":[],"epss":{"score":0.00434,"percentile":0.3744,"date":"2026-10-26","history":[{"date":"2026-09-24","score":0.00434,"percentile":0.34936}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-23T19:19:16.000Z","detail":{"score":"6.5","severity":"MEDIUM","publishedAt":"2026-09-23T19:19:15.700Z"},"summary":"New CVE, medium severity (CVSS 6.5)."}],"references":[{"url":"https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/pull/2012","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/pull/2018","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/releases/tag/4.3.1","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/releases/tag/jline-3.30.15","source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/security/advisories/GHSA-ph9c-7hw9-vhhw","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77421","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}