Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.43% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-77421High confidence
JLine: ReDoS in Nano Editor Regex Search Mode
jline · jline3
Official source article: GitHub GHSA-PH9C-7HW9-VHHW ↗. Check the applicable product and release in the original source.
6.5MediumCVSS 3.1
Scheduled
Fix not verifiedMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs jline jline3 and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
15 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | jline | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian trixietrixie · source | jline2 | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian trixietrixie · source | jline3 | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian bookwormbookworm · source | jline | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian bookwormbookworm · source | jline2 | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian bookwormbookworm · source | jline3 | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian forkyforky · source | jline | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian forkyforky · source | jline2 | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian forkyforky · source | jline3 | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian sidsid · source | jline | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian sidsid · source | jline2 | Not affectedDebian marks this release not affected (fixed-version marker 0). | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian sidsid · source | jline3 | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | jline | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 8 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | jline2 | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 8 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | jline3 | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 8 Oct 2026 |
Open-source package ranges4 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Mavenorg.jline:jline-builtins | ECOSYSTEM: introduced 4.0.0; fixed 4.3.1 | 4.3.1 | OSV record ↗aggregator derived · 23 Sep 2026 |
| Mavenorg.jline:jline-builtins | ECOSYSTEM: introduced 3.0.0; fixed 3.30.15 | 3.30.15 | OSV record ↗aggregator derived · 23 Sep 2026 |
| mavenorg.jline:jline-builtins | >= 4.0.0, < 4.3.1 | 4.3.1 | GitHub advisory ↗upstream repository advisory · 23 Sep 2026 |
| mavenorg.jline:jline-builtins | >= 3.0.0, < 3.30.15 | 3.30.15 | GitHub advisory ↗upstream repository advisory · 23 Sep 2026 |
Direct vendor intelligence
2 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2026-77421 · CSAF 2.0 · revision 2 · interimSUSE Product Security TeamCVE-2026-77421
The vendor explicitly identifies these products as affected by this CVE.
- jline3 as component of SUSE Linux Enterprise Server 16.0
- jline3-builtins as component of SUSE Linux Enterprise Server 16.0
- jline3-console as component of SUSE Linux Enterprise Server 16.0
- jline3-console-ui as component of SUSE Linux Enterprise Server 16.0
- jline3-curses as component of SUSE Linux Enterprise Server 16.0
- jline3-jansi as component of SUSE Linux Enterprise Server 16.0
- jline3-jansi-core as component of SUSE Linux Enterprise Server 16.0
- jline3-javadoc as component of SUSE Linux Enterprise Server 16.0
- jline3-native as component of SUSE Linux Enterprise Server 16.0
- jline3-parent as component of SUSE Linux Enterprise Server 16.0
- jline3-reader as component of SUSE Linux Enterprise Server 16.0
- jline3-remote-telnet as component of SUSE Linux Enterprise Server 16.0
- Summary
- 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 nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.
- Remediation
- No remediation text is recorded.
CVE-2026-77421 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityorg.jline/jline-builtins: JLine: Denial of Service in Nano Editor Regex Search
The vendor explicitly identifies these products as affected by this CVE.
- jline-builtins as a component of Red Hat AMQ Broker 7
- jline-reader as a component of Red Hat AMQ Broker 7
- jline-builtins as a component of Red Hat Fuse 7
- jline-reader as a component of Red Hat Fuse 7
- rhoai/odh-spark-operator-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th-torch-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th-torch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th06-cpu-torch210-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th06-cpu-torch291-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th06-cuda130-torch210-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th06-cuda130-torch291-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- rhoai/odh-th06-rocm64-torch291-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
- Summary
- A flaw was found in the JLine built-in nano editor's regular expression (regex) search mode. A remote attacker could exploit this by providing a specially crafted search term. This could lead to excessive central processing unit (CPU) consumption, causing the editor session to become unresponsive and potentially leading to a denial of service (DoS) for affected users or worker threads in multi-user deployments.
- Remediation
- Do not expose the JLine built-in nano editor to untrusted users. If applications embedding JLine must provide an interactive editor, disable the regex search mode or restrict editor access to authenticated and trusted users only.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Fix not verified01
What, why and how
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 nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.
What
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 nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.
Why
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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 nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.
Why
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Inefficient Regular Expression Complexity → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-1333 ↗
CWE-1333: Inefficient Regular Expression Complexity. The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- jline3 as component of SUSE Linux Enterprise Server 16.0
- jline3-builtins as component of SUSE Linux Enterprise Server 16.0
- jline3-console as component of SUSE Linux Enterprise Server 16.0
- jline3-console-ui as component of SUSE Linux Enterprise Server 16.0
- jline3-curses as component of SUSE Linux Enterprise Server 16.0
- jline3-jansi as component of SUSE Linux Enterprise Server 16.0
- jline3-jansi-core as component of SUSE Linux Enterprise Server 16.0
- jline3-javadoc as component of SUSE Linux Enterprise Server 16.0
- jline3-native as component of SUSE Linux Enterprise Server 16.0
- jline3-parent as component of SUSE Linux Enterprise Server 16.0
- jline3-reader as component of SUSE Linux Enterprise Server 16.0
- jline3-remote-telnet as component of SUSE Linux Enterprise Server 16.0
- jline3-style as component of SUSE Linux Enterprise Server 16.0
- jline3-terminal as component of SUSE Linux Enterprise Server 16.0
- jline3-terminal-jansi as component of SUSE Linux Enterprise Server 16.0
- jline3-terminal-jna as component of SUSE Linux Enterprise Server 16.0
- jline3-terminal-jni as component of SUSE Linux Enterprise Server 16.0
- jline3 as component of SUSE Linux Enterprise Server 16.1
- jline3-builtins as component of SUSE Linux Enterprise Server 16.1
- jline3-console as component of SUSE Linux Enterprise Server 16.1
- jline3-console-ui as component of SUSE Linux Enterprise Server 16.1
- jline3-curses as component of SUSE Linux Enterprise Server 16.1
- jline3-jansi as component of SUSE Linux Enterprise Server 16.1
- jline3-jansi-core as component of SUSE Linux Enterprise Server 16.1
- jline3-javadoc as component of SUSE Linux Enterprise Server 16.1
- jline3-native as component of SUSE Linux Enterprise Server 16.1
- jline3-reader as component of SUSE Linux Enterprise Server 16.1
- jline3-remote-telnet as component of SUSE Linux Enterprise Server 16.1
- jline3-style as component of SUSE Linux Enterprise Server 16.1
- jline3-terminal as component of SUSE Linux Enterprise Server 16.1
- and 37 more
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 23 Sept 2026 · Last source change 23 Sept 2026, 19:43 UTC · CWE-1333 · Inefficient Regular Expression Complexity
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-24
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-85522
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-85522 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-85522"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.