CVE-2026-77420

Name	CVE-2026-77420
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
jline (PTS)	forky, sid, bookworm, trixie	1.0-3	fixed
jline2 (PTS)	bookworm	2.14.6-5	fixed
	forky, sid, trixie	2.14.6-6	fixed
jline3 (PTS)	bookworm	3.3.1-3	vulnerable
	trixie	3.3.1-4	vulnerable
	forky, sid	3.3.1-5	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
jline	source	(unstable)	(not affected)
jline2	source	(unstable)	(not affected)
jline3	source	(unstable)	(unfixed)

Notes

- jline2 <not-affected> (HISTORY_IGNORE was introduced in 3.x)
- jline <not-affected> (HISTORY_IGNORE was introduced in 3.x)
https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3
https://github.com/jline/jline3/pull/2018
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae