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18Track

JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable

jline3 · CVE-2026-77420
0 news outlets0 CERTs and agencies0 researchers

Assessment: Track

SSVC decision points: exploitation poc, automatable no, technical impact partial, deployment low.

What is 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.

Evidence

No coverage recorded yet.

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
5.5
EPSS
0.1%
First seen
11 h ago
Status
corroborated

All jline vulnerabilities