CVE-2026-77420

Description

JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configuration value into a Java regular expression while escaping only part of its syntax, allowing other regex metacharacters to reach the backtracking engine. An attacker who can control application or user configuration can supply a nested-quantifier expression that is reevaluated whenever a command is added to history, consuming excessive CPU and indefinitely blocking the reader thread. This issue is fixed in versions 3.30.15 and 4.3.1.

Overview

State: PUBLISHED
Assigner (CNA): GitHub_M
CVSS severity: MEDIUM
CVSS score: 5.5 / 10
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Effective score: 5.5 / 10 MEDIUM source: CNA overview
CWE(s): CWE-1333
Reserved: 2026-08-20
Published: 2026-09-23 18:11 UTC
Last updated: 2026-09-23 18:11 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/77xxx/CVE-2026-77420.json

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-23 19:19:15 UTC
NVD last modified: 2026-09-23 19:19:15 UTC
NVD CVSS v3.1: 5.5 / 10 MEDIUM source: security-advisories@github.com
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 1.8 / 10
Impact subscore: 3.6 / 10

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-85528
Assigner: GitHub_M
Published: Sep 23, 2026, 6:11:25 PM
Updated: Sep 23, 2026, 6:11:25 PM
EUVD base score (CVSS 3.1): 5.5 / 10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EUVD-reported EPSS: 0.0000
Vendors: jline
Products: jline3 (4.0.0, < 4.3.1)

jline3 (3.0.0, < 3.30.15)
Aliases: GHSA-5q95-hrpc-m3w3

ENISA description: JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configuration value into a Java regular expression while escaping only part of its syntax, allowing other regex metacharacters to reach the backtracking engine. An attacker who can control application or user configuration can supply a nested-quantifier expression that is reevaluated whenever a command is added to history, consuming excessive CPU and indefinitely blocking the reader thread. This issue is fixed in versions 3.30.15 and 4.3.1.

EUVD references (7)

Affected products (1)

Vendor	Product	Versions	Platforms
jline	jline3	`>= 3.0.0, < 3.30.15` (affected), `>= 4.0.0, < 4.3.1` (affected)	—

Vendor references (7)

References embedded in the original CVE record by the assigning CNA.

https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3 x_refsource_CONFIRM
https://github.com/jline/jline3/pull/2012 x_refsource_MISC
https://github.com/jline/jline3/pull/2018 x_refsource_MISC
https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541 x_refsource_MISC
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae x_refsource_MISC
https://github.com/jline/jline3/releases/tag/4.3.1 x_refsource_MISC
https://github.com/jline/jline3/releases/tag/jline-3.30.15 x_refsource_MISC

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (7)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541 security-advisories@github.com
https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae security-advisories@github.com
https://github.com/jline/jline3/pull/2012 security-advisories@github.com
https://github.com/jline/jline3/pull/2018 security-advisories@github.com
https://github.com/jline/jline3/releases/tag/4.3.1 security-advisories@github.com
https://github.com/jline/jline3/releases/tag/jline-3.30.15 security-advisories@github.com
https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3 security-advisories@github.com

Remediations (10)

CVE-2026-68820 Is in KEV. What BOD 26-04 Requires Now | Qualys

web:blog.qualys.com

Executive Summary CVE - 2026 -68820 is an actively exploited Windows vulnerability listed in CISA's Known Exploited Vulnerabilities (KEV) Catalog, with a remediation deadline as suggested by CISA BOD 26-04. CISA BOD 26-04 introduces risk-based remediation timelines ranging from 3 to 14 days, increasing the pressure on teams to move quickly from patch availability to verified remediation ...

2026-09-24 11:50 UTC
CISA Requires Federal Agencies to Patch Critical Vulnerabilities Within ...

web:cybersecuritynews.com

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has issued Binding Operational Directive (BOD) 26-04, titled "Prioritizing Security Updates Based on Risk," compelling all Federal Civilian Executive Branch (FCEB) agencies to remediate the most dangerous known exploited vulnerabilities within just three calendar days.

2026-09-24 11:50 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-24 11:50 UTC
March 10, 2026—Hotpatch KB5079420 (OS Builds 26200.7979 and 26100.7979 ...

web:support.microsoft.com

This Hotpatch update for Windows 11, version 25H2 and 24H2 (KB5079420), improves functionality, performance, and reliability. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of ...

2026-09-24 11:50 UTC
SAP Security Patch Day - June 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 9th of June 2026 , SAP security patch day saw the release of 15 new security notes.

2026-09-24 11:50 UTC
Microsoft Update Catalog

web:www.catalog.update.microsoft.com

If you have a pop-up blocker enabled, the Update Details window might not open. To open the Update Details window, configure your pop-blocker to allow pop-ups for this Web site. AddAdd AllRemoveRemove All

2026-09-24 11:50 UTC
Critical Patches Issued for Microsoft Products, August 11, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-09-24 11:50 UTC
Vulnerability Detection and Response - FedRAMP Consolidated Rules for 2026

web:www.fedramp.gov

Ruleset Reference 20x 20x Class C Boundary Rulesets Vulnerability Detection and Response The Vulnerability Detection and Response rules require providers to continuously identify, analyze, prioritize, mitigate, and remediate vulnerabilities and related exposures through automated systems. These rules give providers flexibility in implementation while ensuring agencies receive the information ...

2026-09-24 11:50 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-09-24 11:50 UTC
Patch Tuesday - August 2026 - Rapid7

web:www.rapid7.com

Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday, including 236 vulnerabilities in Windows. Rapid7 has disclosed the second in a two-part critical remote execution vulnerability chain in SharePoint.

2026-09-24 11:50 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-77420.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "jline3",
          "vendor": "jline",
          "versions": [
            {
              "status": "affected",
              "version": ">= 3.0.0, < 3.30.15"
            },
            {
              "status": "affected",
              "version": ">= 4.0.0, < 4.3.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, DefaultHistory.matchPatterns(String patterns, String line) in reader/src/main/java/org/jline/reader/impl/history/DefaultHistory.java converts the HISTORY_IGNORE configuration value into a Java regular expression while escaping only part of its syntax, allowing other regex metacharacters to reach the backtracking engine. An attacker who can control application or user configuration can supply a nested-quantifier expression that is reevaluated whenever a command is added to history, consuming excessive CPU and indefinitely blocking the reader thread. This issue is fixed in versions 3.30.15 and 4.3.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333: Inefficient Regular Expression Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-23T18:11:25.998Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/jline/jline3/security/advisories/GHSA-5q95-hrpc-m3w3"
        },
        {
          "name": "https://github.com/jline/jline3/pull/2012",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/pull/2012"
        },
        {
          "name": "https://github.com/jline/jline3/pull/2018",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/pull/2018"
        },
        {
          "name": "https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/commit/1d5fc3099e77938b971e197211cad2d4fbb17541"
        },
        {
          "name": "https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/commit/341ee69ccc57b7733c1b40d6993219b64b3206ae"
        },
        {
          "name": "https://github.com/jline/jline3/releases/tag/4.3.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/releases/tag/4.3.1"
        },
        {
          "name": "https://github.com/jline/jline3/releases/tag/jline-3.30.15",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jline/jline3/releases/tag/jline-3.30.15"
        }
      ],
      "source": {
        "advisory": "GHSA-5q95-hrpc-m3w3",
        "discovery": "UNKNOWN"
      },
      "title": "JLine: ReDoS via `HISTORY_IGNORE` Configuration Variable"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-77420",
    "datePublished": "2026-09-23T18:11:25.998Z",
    "dateReserved": "2026-08-20T19:59:59.603Z",
    "dateUpdated": "2026-09-23T18:11:25.998Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}