CVE-2026-77421

Name	CVE-2026-77421
Description	JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, the JLine built-in nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. 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> (Nano editor was introduced in 3.x)
- jline <not-affected> (Nano editor was introduced in 3.x)
https://github.com/jline/jline3/security/advisories/GHSA-ph9c-7hw9-vhhw
https://github.com/jline/jline3/pull/2018
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae