CVE-2026-77420
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
23/09/2026
Last modified:
30/09/2026
Description
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.
Impact
Base Score 3.x
5.50
Severity 3.x
MEDIUM
References to Advisories, Solutions, and Tools
- https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541
- https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae
- https://github.com/jline/jline3/pull/2012
- https://github.com/jline/jline3/pull/2018
- https://github.com/jline/jline3/releases/tag/4.3.1
- https://github.com/jline/jline3/releases/tag/jline-3.30.15
- https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3
- https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3