JLine3 Telnet server: Unauthenticated Remote Memory Exhaustion via Unbounded Telnet NEW-ENVIRON Variables

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0059, the 48th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:16 UTC First seen by agentprime
2. 31 Oct 2026, 14:16 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-47qp-hqvx-6r3f
• OSV: GHSA-47qp-hqvx-6r3f
• github.com/jline/jline3/security/advisories/GHSA-47qp-hqvx-6r3f
• nvd.nist.gov/vuln/detail/CVE-2026-56740
• github.com/jline/jline3/pull/2000
• github.com/jline/jline3/pull/2001
• github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09
• github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40
• github.com/jline/jline3/commit/934f09e6128cee33c2b13d42b6e859c1ee2d194b
• github.com/jline/jline3
• github.com/jline/jline3/releases/tag/4.0.16
• github.com/jline/jline3/releases/tag/4.2.1
• github.com/jline/jline3/releases/tag/jline-3.30.14

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.