JLine up to 3.30.14/4.3.0 Regex Search Nano.java doSearch text resource consumption

Summaryinfo

A vulnerability was found in JLine up to 3.30.14/4.3.0. It has been declared as problematic. The impacted element is the function doSearch of the file builtins/src/main/java/org/jline/builtins/Nano.java of the component Regex Search. The manipulation of the argument text results in resource consumption. This vulnerability is identified as CVE-2026-77421. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in JLine up to 3.30.14/4.3.0. Affected is the function doSearch of the file builtins/src/main/java/org/jline/builtins/Nano.java of the component Regex Search. The manipulation of the argument text with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-77421 since 08/20/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 3.30.15 or 4.3.1 eliminates this vulnerability.

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Productinfo

Name

• JLine

Version

• 3.30.0
• 3.30.1
• 3.30.2
• 3.30.3
• 3.30.4
• 3.30.5
• 3.30.6
• 3.30.7
• 3.30.8
• 3.30.9
• 3.30.10
• 3.30.11
• 3.30.12
• 3.30.13
• 3.30.14
• 4.0
• 4.1
• 4.2
• 4.3.0

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