Medium 5.5Published Sep 23, 2026

CVE-2026-77420JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable

Updated under an hour ago (2026-10-19 09:20 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configuration value into a Java regular expression while escaping only part of its syntax, allowing other regex metacharacters to reach the backtracking engine. An attacker who can control application or user configuration can supply a nested-quantifier expression that is reevaluated whenever a command is added to history, consuming excessive CPU and indefinitely blocking the reader thread. This issue is fixed in versions 3.30.15 and 4.3.1.

CVSS: 5.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-1333
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Sep 29, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

jline jline3 jline:jline3 (from the name)	from 3.0.0, < 3.30.15; from 4.0.0, < 4.3.1	CNA record

References

https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3x-refsource-confirm
https://github.com/jline/jline3/pull/2012x-refsource-misc
https://github.com/jline/jline3/pull/2018x-refsource-misc
https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541x-refsource-misc
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206aex-refsource-misc
https://github.com/jline/jline3/releases/tag/4.3.1x-refsource-misc
https://github.com/jline/jline3/releases/tag/jline-3.30.15x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.