CVE-2026-77423
JLine: ReDoS in Built-in Less Viewer Search
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
JLine: ReDoS in Built-in Less Viewer Search
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.
- Record
CVE-2026-77423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
EUVDEUVD-2026-85531
7.5
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.
- Record
EUVD-2026-85531- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-77423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
OSV
7.5
JLine: ReDoS in Built-in Less Viewer Search
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.
- Record
CVE-2026-77423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-77423
7.5
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.
- Record
DEBIAN-CVE-2026-77423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-77423
7.5
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.
- Record
UBUNTU-CVE-2026-77423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
jline3Debian:12 |
All versions, plus listed versions 3.3.1-33.3.1-43.3.1-5 |
None known |
jline3Debian:13 |
All versions, plus listed versions 3.3.1-43.3.1-5 |
None known |
jline3Debian:14 |
All versions, plus listed versions 3.3.1-43.3.1-5 |
None known |
jlineUbuntu:14.04:LTS |
All versions, plus listed versions 1.0-2 |
None known |
jline2Ubuntu:14.04:LTS |
All versions, plus listed versions 2.11-12.11-2 |
None known |
jlineUbuntu:16.04:LTS |
All versions, plus listed versions 1.0-2 |
None known |
jline2Ubuntu:16.04:LTS |
All versions, plus listed versions 2.11-4 |
None known |
jlineUbuntu:18.04:LTS |
All versions, plus listed versions 1.0-2 |
None known |
jline2Ubuntu:18.04:LTS |
All versions, plus listed versions 2.11-42.12.1-12.14.6-1 |
None known |
jlineUbuntu:20.04:LTS |
All versions, plus listed versions 1.0-2 |
None known |
Show 13 moreShow less
| Package | Affected | Fixed |
|---|---|---|
jline2Ubuntu:20.04:LTS |
All versions, plus listed versions 2.14.6-3 |
None known |
jlineUbuntu:22.04:LTS |
All versions, plus listed versions 1.0-3 |
None known |
jline2Ubuntu:22.04:LTS |
All versions, plus listed versions 2.14.6-4 |
None known |
jline3Ubuntu:22.04:LTS |
All versions, plus listed versions 3.3.1-2 |
None known |
jlineUbuntu:24.04:LTS |
All versions, plus listed versions 1.0-3 |
None known |
jline2Ubuntu:24.04:LTS |
All versions, plus listed versions 2.14.6-5 |
None known |
jline3Ubuntu:24.04:LTS |
All versions, plus listed versions 3.3.1-33.3.1-3ubuntu1 |
None known |
jlineUbuntu:26.10 |
All versions, plus listed versions 1.0-3build1 |
None known |
jline2Ubuntu:26.10 |
All versions, plus listed versions 2.14.6-6 |
None known |
jline3Ubuntu:26.10 |
All versions, plus listed versions 3.3.1-4build13.3.1-5 |
None known |
jlineUbuntu:26.04:LTS |
All versions, plus listed versions 1.0-31.0-3build1 |
None known |
jline2Ubuntu:26.04:LTS |
All versions, plus listed versions 2.14.6-6 |
None known |
jline3Ubuntu:26.04:LTS |
All versions, plus listed versions 3.3.1-43.3.1-4build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-77423 is a high vulnerability (CVSS 7.5) in Jline Jline3, published September 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. No source names a fixed version.
References
github.com/jline/jline3/security/advisories/GHSA-2v9w-34q6-wpqx
github.com/jline/jline3/pull/2012
github.com/jline/jline3/pull/2018
github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541
github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae
github.com/jline/jline3/releases/tag/4.3.1