SB2026090936 - Multiple vulnerabilities in jline3
Published: September 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Inefficient regular expression complexity (CVE-ID: CVE-2026-77420)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in the DefaultHistory.matchPatterns() method when processing a crafted HISTORY_IGNORE configuration value while adding a command line to history. A local user can configure a malicious HISTORY_IGNORE pattern to cause a denial of service.
Applications embedding the jline-reader component are affected only when HISTORY_IGNORE can be configured through user configuration or application settings.
2) Inefficient regular expression complexity (CVE-ID: CVE-2026-77421)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in the nano editor\'s doSearch(String text) function when processing a user-supplied regular expression in regex search mode. A remote user can enter a crafted nested-quantifier regular expression to cause a denial of service.
Regex search mode must be enabled, and non-matching buffer content can trigger catastrophic backtracking.
3) Inefficient regular expression complexity (CVE-ID: CVE-2026-77422)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in the built-in grep command\'s pattern handling when processing a crafted regular expression against non-matching input. A remote attacker can submit a regular expression that causes catastrophic backtracking to cause a denial of service.
Exploitation can cause the command thread to consume high CPU and stop responding.
4) Inefficient regular expression complexity (CVE-ID: CVE-2026-77423)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in the JLine3 built-in less viewer\'s Less.getPattern() method when processing user-supplied search patterns. A remote attacker can submit a regular expression with nested quantifiers to cause a denial of service.
The compiled pattern is repeatedly applied against file content and can cause catastrophic backtracking.
Remediation
Install update from vendor's website.