---
id: CVE-2026-77422
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 grep command in
  builtins/src/main/java/org/jline/builtins/PosixCommands.java accepts a
  user-controlled regular expression in grep(…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/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: '2026-09-24'
sourceUpdated: '2026-09-24T14:18:17.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77422'
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-r2xf-8xr9-62gw'
    label: security-advisories@github.com
  - url: 'https://github.com/jline/jline3/security/advisories/GHSA-r2xf-8xr9-62gw'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-r2xf-8xr9-62gw'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77422.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-77422'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2539620'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-77422'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77422'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - maven
  - csaf
  - vex
  - red-hat
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-24T14:13:32.954382Z'
aliases:
  - GHSA-r2xf-8xr9-62gw
ecosystem: maven
ingestedAt: '2026-09-23T18:29:33.150Z'
epss: 0.00496
epssPercentile: 0.39903
---

## 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 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.

## Remediation

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

## Package advisory (CVE-2026-77422)

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-r2xf-8xr9-62gw

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Fuse 7, Red Hat OpenShift AI (RHOAI), Red Hat OpenStack Platform 13 (Queens) · no fix planned: Red Hat Fuse 7, Red Hat OpenStack Platform 13 (Queens), Red Hat OpenShift AI (RHOAI) · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77422.json)