CVE-2026-77422

Name	CVE-2026-77422
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 grep command in builtins/src/main/java/org/jline/builtins/PosixCommands.java accepts a user-controlled regular expression in grep(...) and, unless line-regexp mode is used, automatically adds a dot-star prefix and suffix before compiling it with Java's backtracking regular expression engine. The wrapping expands the backtracking search space, so a short nested-quantifier expression evaluated against non-matching input can consume excessive CPU and indefinitely block a command worker, including in remotely exposed shell sessions. 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> (Grep command was introduced in 3.x)
- jline <not-affected> (Grep command was introduced in 3.x)
https://github.com/jline/jline3/security/advisories/GHSA-r2xf-8xr9-62gw
https://github.com/jline/jline3/pull/2018
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae