CVE-2026-77420
JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable
MEDIUM 5.5EPSS 0.1%
JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configuration value into a Java regular expression while escaping only part of its syntax, allowing other regex metacharacters to reach the backtracking engine. An attacker who can control application or user configuration can supply a nested-quantifier expression that is reevaluated whenever a command is added to history, consuming excessive CPU and indefinitely blocking the reader thread. This issue is fixed in versions 3.30.15 and 4.3.1.
- Affected
- jline · jline3
- CVSS v3.1 GITHUB
- 5.5 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.12% chance of exploitation in the next 30 days, 2nd percentile
- Published
- 2026-09-23
- Updated
- 2026-09-29