CVE-2026-77421

medium

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.

References

https://github.com/jline/jline3/security/advisories/GHSA-ph9c-7hw9-vhhw

https://github.com/jline/jline3/releases/tag/jline-3.30.15

https://github.com/jline/jline3/releases/tag/4.3.1

https://github.com/jline/jline3/pull/2018

https://github.com/jline/jline3/pull/2012

https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae

https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541

Details

Source: Mitre, NVD

Published: 2026-09-23

Updated: 2026-09-23

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00434