CVE-2026-56741
JLine: Unauthenticated Remote DoS via Unbounded Telnet NAWS Terminal Geometry
02 Description
JLine: Unauthenticated Remote DoS via Unbounded Telnet NAWS Terminal Geometry
03 Exploitation and scoring
- Exploitation
- Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
- SSVC decision
- ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.59% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 48.3% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-10-24.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-07-17 21:15Z3 MO AGO
- Last updated
- 2026-07-20 15:21Z3 MO AGO
- Reserved
- 2026-06-22
- Assigning CNA
- GitHub_M
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.5)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- Data version
- 5.2
- Document digest
- c4eb3099390d4233b3bed07092a9b360bc5dd552aa7a0066811bdedc11bbce6c
05 Affected products
06 References
- github.comhttps://github.com/jline/jline3/security/advisories/GHSA-2r2c-cx56-8933
- github.comhttps://github.com/jline/jline3/pull/2000
- github.comhttps://github.com/jline/jline3/commit/3ea9cad8699714dc072fade29d36be0d1e23d708
- github.comhttps://github.com/jline/jline3/commit/733eb353dca7b0ea0252e724445b6defa29c393e
- github.comhttps://github.com/jline/jline3/commit/86b7ba7801988aadb1a67555629522a71d603bd3
- github.comhttps://github.com/jline/jline3/releases/tag/4.0.16
- github.comhttps://github.com/jline/jline3/releases/tag/4.2.1
07 Fixed in
Debian 12
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 14.04 LTS
- jline No fix yet
- jline2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- jline No fix yet
- jline2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- jline No fix yet
- jline2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- jline No fix yet
- jline2 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- jline No fix yet
- jline2 No fix yet
- jline3 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.