Answer in brief
CVE-2026-77420 records a Medium severity (CVSS 5.5) vulnerability in JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable. The current sources do not mark it as known exploited. The current feed maps jline/jline3 (generic), org.jline:jline-reader (maven), org.jline:jline-reader (maven), org.jline:jline-reader (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps jline/jline3 (generic), org.jline:jline-reader (maven), org.jline:jline-reader (maven), org.jline:jline-reader (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| jline/jline3generic | >=3.0.0 <3.30.15 || >=4.0.0 <4.3.1 | 3.30.15, 4.3.1 |
| org.jline:jline-readermaven | >=4.0.0,<4.3.1 | 4.3.1 |
| org.jline:jline-readermaven | >=3.0.0,<3.30.15 | 3.30.15 |
| org.jline:jline-readermaven | >=4.0.0 <4.3.1 | 4.3.1 |
| org.jline:jline-readermaven | >=3.0.0 <3.30.15 | 3.30.15 |
Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 23, 2026
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.
Quoted source text, attributed separately from HOL analysis.