[ CVE-2026-77423 · Published 23 Sep 2026 ]
Vulnerability in jline3
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
[ Description ]Official 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 less viewer passes user-controlled search and display-filter patterns from getPattern(boolean doDisplayPattern) in builtins/src/main/java/org/jline/builtins/Less.java directly to Java's backtracking regular expression engine and repeatedly applies them to file content. A nested-quantifier expression evaluated against non-matching lines can consume excessive CPU and indefinitely block the session thread, and repeated sessions in Telnet or SSH deployments can exhaust a bounded worker pool. This issue is fixed in versions 3.30.15 and 4.3.1.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.
[ References ]References
- github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541
- github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae
- github.com/jline/jline3/pull/2012
- github.com/jline/jline3/pull/2018
- github.com/jline/jline3/releases/tag/4.3.1
- github.com/jline/jline3/releases/tag/jline-3.30.15
- github.com/jline/jline3/security/advisories/GHSA-2v9w-34q6-wpqx