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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-r2xf-8xr9-62gw JLine: ReDoS in Built-in grep Command Amplified by Automatic `.*` Wrapping
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 23 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
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.
Title JLine: ReDoS in Built-in grep Command Amplified by Automatic `.*` Wrapping
Weaknesses CWE-1333
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-23T18:09:32.308Z

Reserved: 2026-08-20T19:59:59.603Z

Link: CVE-2026-77422

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-23T19:19:15.863

Modified: 2026-09-23T19:19:15.863

Link: CVE-2026-77422

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-23T20:45:09Z

Weaknesses