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CVE-2026-77420mediumCWE-1333

JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable

10Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 5.5
exploitation probability
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected products
jline · jline3