CVE-2026-56740
- Source
- https://cve.org/CVERecord?id=CVE-2026-56740
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56740.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-56740
- Aliases
- Downstream
- Related
- Published
- 2026-07-17T21:17:03.239Z
- Modified
- 2026-07-23T09:59:46.612750840Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- JLine: Unauthenticated Remote Memory Exhaustion via Unbounded Telnet NEW-ENVIRON Variables
- Details
-
JLine is a Java library for handling console input. Prior to 3.30.14, 4.0.16, and 4.2.1, the JLine3 Telnet server remote-telnet module does not limit the number of environment variables a client may inject via the Telnet NEW-ENVIRON option, and TelnetIO.readNEVariables() in TelnetIO.java:1127-1180 stores each variable pair in a HashMap held by ConnectionData, allowing an unauthenticated attacker to flood unique variable pairs before the terminating IAC SE byte and exhaust JVM heap memory with an OutOfMemoryError. This issue is fixed in versions 3.30.14, 4.0.16, and 4.2.1.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56740.json", "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-400" ] }- References
-
- https://github.com/jline/jline3/releases/tag/4.0.16
- https://github.com/jline/jline3/releases/tag/4.2.1
- https://github.com/jline/jline3/releases/tag/jline-3.30.14
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56740.json
- https://github.com/jline/jline3/security/advisories/GHSA-47qp-hqvx-6r3f
- https://nvd.nist.gov/vuln/detail/CVE-2026-56740
- https://github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09
- https://github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40
- https://github.com/jline/jline3/commit/934f09e6128cee33c2b13d42b6e859c1ee2d194b
- https://github.com/jline/jline3/pull/2000
- https://github.com/jline/jline3/pull/2001
Affected packages
Git / github.com/jline/jline3
Affected ranges
- Type
- GIT
- Repo
- https://github.com/jline/jline3
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedIntroducedIntroducedFixedFixedFixedFixedFixedFixed
- Database specific
{ "source": [ "AFFECTED_FIELD", "REFERENCES" ], "extracted_events": [ { "introduced": "0" }, { "fixed": "3.30.14" }, { "introduced": "4.0.0" }, { "fixed": "4.0.16" }, { "introduced": "4.1.0" }, { "fixed": "4.2.1" } ] }
Affected versions
4.*
4.0.0
4.0.0-SNAPSHOT
4.0.1
4.0.10
4.0.11
4.0.12
4.0.13
4.0.14
4.0.15
4.0.2
4.0.3
4.0.4
4.0.5
4.0.6
4.0.7
4.0.8
4.0.9
4.1.0
4.1.0-SNAPSHOT
4.1.1
4.1.2
4.1.3
4.2.0
jline-3.*
jline-3.0.0
jline-3.0.0.M1
jline-3.0.0.M2
jline-3.0.1
jline-3.1.0
jline-3.1.1
jline-3.27.0
jline-3.27.1
jline-3.28.0
jline-3.29.0
jline-3.3.1
jline-3.30.0
jline-3.30.1
jline-3.30.10
jline-3.30.11
jline-3.30.12
jline-3.30.13
jline-3.30.2
jline-3.30.3
jline-3.30.4
jline-3.30.5
jline-3.30.6
jline-3.30.7
jline-3.30.8
jline-3.30.9
jline-parent-3.*
jline-parent-3.10.0
jline-parent-3.11.0
jline-parent-3.12.0
jline-parent-3.12.1
jline-parent-3.13.0
jline-parent-3.13.1
jline-parent-3.13.2
jline-parent-3.13.3
jline-parent-3.14.0
jline-parent-3.14.1
jline-parent-3.16.0
jline-parent-3.17.0
jline-parent-3.17.1
jline-parent-3.18.0
jline-parent-3.19.0
jline-parent-3.2.0
jline-parent-3.20.0
jline-parent-3.21.0
jline-parent-3.22.0
jline-parent-3.23.0
jline-parent-3.24.0
jline-parent-3.24.1
jline-parent-3.25.0
jline-parent-3.25.1
jline-parent-3.26.0
jline-parent-3.26.1
jline-parent-3.26.2
jline-parent-3.26.3
jline-parent-3.3.0
jline-parent-3.4.0
jline-parent-3.5.0
jline-parent-3.5.1
jline-parent-3.5.2
jline-parent-3.6.0
jline-parent-3.6.1
jline-parent-3.6.2
jline-parent-3.7.0
jline-parent-3.7.1
jline-parent-3.8.0
jline-parent-3.8.1
jline-parent-3.8.2
jline-parent-3.9.0
Database specific
vanir_signatures
[
{
"digest": {
"length": 1474.0,
"function_hash": "9659067575893753802717095945310300604"
},
"signature_version": "v1",
"deprecated": false,
"signature_type": "Function",
"target": {
"function": "readNEVariables",
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-05baba86",
"source": "https://github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40"
},
{
"digest": {
"threshold": 0.9,
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]
},
"signature_version": "v1",
"deprecated": false,
"signature_type": "Line",
"target": {
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-40600949",
"source": "https://github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09"
},
{
"digest": {
"length": 1484.0,
"function_hash": "18293505911945577055547336982745324144"
},
"signature_version": "v1",
"deprecated": false,
"signature_type": "Function",
"target": {
"function": "readNEVariables",
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-7cfd139e",
"source": "https://github.com/jline/jline3/commit/934f09e6128cee33c2b13d42b6e859c1ee2d194b"
},
{
"digest": {
"length": 1474.0,
"function_hash": "9659067575893753802717095945310300604"
},
"signature_version": "v1",
"source": "https://github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09",
"signature_type": "Function",
"target": {
"function": "readNEVariables",
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-820c2de1",
"deprecated": false
},
{
"digest": {
"threshold": 0.9,
"line_hashes": [
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"261354662018613459591414882692417150585"
]
},
"signature_version": "v1",
"source": "https://github.com/jline/jline3/commit/934f09e6128cee33c2b13d42b6e859c1ee2d194b",
"signature_type": "Line",
"target": {
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-ae6eeaea",
"deprecated": false
},
{
"digest": {
"length": 347.0,
"function_hash": "236413241627164877253365168930117531644"
},
"signature_version": "v1",
"deprecated": false,
"signature_type": "Function",
"target": {
"function": "setTerminalGeometry",
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-d70e878e",
"source": "https://github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40"
},
{
"digest": {
"threshold": 0.9,
"line_hashes": [
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"129486502375561182486208346847798694875",
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"254285511972821347395851233230491879827",
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]
},
"signature_version": "v1",
"deprecated": false,
"signature_type": "Line",
"target": {
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-ea21c22f",
"source": "https://github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40"
},
{
"digest": {
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"function_hash": "236413241627164877253365168930117531644"
},
"signature_version": "v1",
"source": "https://github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09",
"signature_type": "Function",
"target": {
"function": "setTerminalGeometry",
"file": "remote-telnet/src/main/java/org/jline/builtins/telnet/TelnetIO.java"
},
"id": "CVE-2026-56740-ec9360e5",
"deprecated": false
}
]
vanir_signatures_modified
"2026-07-22T08:04:25Z"
source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56740.json"