---
id: CVE-2026-77421
title: JLine is a Java library for handling console input
summary: >-
  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/jlin…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1333
vendor: jline
product: jline3
affected:
  - 'jline3 >= 3.0.0, < 3.30.15'
  - 'jline3 >= 4.0.0, < 4.3.1'
patched:
  - 'org.jline:jline-builtins 4.3.1'
  - 'org.jline:jline-builtins 3.30.15'
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:15.777'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77421'
references:
  - url: >-
      https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541
    label: security-advisories@github.com
  - url: >-
      https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/pull/2012'
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/pull/2018'
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/releases/tag/4.3.1'
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/releases/tag/jline-3.30.15'
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/security/advisories/GHSA-ph9c-7hw9-vhhw'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-ph9c-7hw9-vhhw'
tags:
  - nvd
  - cve.org
  - ghsa
  - maven
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T19:05:07.485942Z'
aliases:
  - GHSA-ph9c-7hw9-vhhw
ecosystem: maven
ingestedAt: '2026-09-23T18:29:33.150Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-77421)

Affected packages:

- `org.jline:jline-builtins >= 4.0.0, < 4.3.1`
- `org.jline:jline-builtins >= 3.0.0, < 3.30.15`

Patched in:

- `org.jline:jline-builtins 4.3.1`
- `org.jline:jline-builtins 3.30.15`

Source: https://github.com/advisories/GHSA-ph9c-7hw9-vhhw