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Full vulnerability report · 2026
CVE-2026-15972High confidence

Unauthenticated denial of service via unbounded external gRPC connection acceptance

HashiCorp · Consul

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Direct vendor intelligence

Authoritative 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.

1 current
CVE-2026-15972 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityconsul: consul-enterprise: Consul: Denial of Service via unbounded external gRPC connection acceptance
15 known not affected

The vendor explicitly states that these products are not affected by this CVE.

  • grafana as a component of Red Hat Enterprise Linux 8
  • grafana-azure-monitor as a component of Red Hat Enterprise Linux 8
  • grafana-cloudwatch as a component of Red Hat Enterprise Linux 8
  • grafana-elasticsearch as a component of Red Hat Enterprise Linux 8
  • grafana-graphite as a component of Red Hat Enterprise Linux 8
  • grafana-influxdb as a component of Red Hat Enterprise Linux 8
  • grafana-loki as a component of Red Hat Enterprise Linux 8
  • grafana-mssql as a component of Red Hat Enterprise Linux 8
  • grafana-mysql as a component of Red Hat Enterprise Linux 8
  • grafana-opentsdb as a component of Red Hat Enterprise Linux 8
  • grafana-postgres as a component of Red Hat Enterprise Linux 8
  • grafana-prometheus as a component of Red Hat Enterprise Linux 8
Summary
A flaw was found in Consul. A remote attacker can exploit this vulnerability by sending numerous incomplete connection requests to the external gRPC (gRPC Remote Procedure Call) listeners. This unbounded connection acceptance can exhaust agent resources, such as file descriptors, goroutines, and memory. The primary consequence is a denial of service, which prevents legitimate clients from connecting to the Consul agent.
Remediation
No remediation text is recorded.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-54612

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

Consul Community Edition and Consul Enterprise 1.13.0 through 2.0.2 are vulnerable to an unauthenticated denial of service through unbounded connection acceptance on the external gRPC listeners. A remote attacker may exhaust agent file descriptors, goroutines, and memory by opening many incomplete connections, potentially preventing legitimate clients from connecting. This vulnerability, CVE-2026-15972, is fixed in Consul 2.0.3 and Consul Enterprise 1.21.17, 1.22.11, and 2.0.3.

What

Consul Community Edition and Consul Enterprise 1.13.0 through 2.0.2 are vulnerable to an unauthenticated denial of service through unbounded connection acceptance on the external gRPC listeners. A remote attacker may exhaust agent file descriptors, goroutines, and memory by opening many incomplete connections, potentially preventing legitimate clients from connecting. This vulnerability, CVE-2026-15972, is fixed in Consul 2.0.3 and Consul Enterprise 1.21.17, 1.22.11, and 2.0.3.

Why

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Consul Community Edition and Consul Enterprise 1.13.0 through 2.0.2 are vulnerable to an unauthenticated denial of service through unbounded connection acceptance on the external gRPC listeners. A remote attacker may exhaust agent file descriptors, goroutines, and memory by opening many incomplete connections, potentially preventing legitimate clients from connecting. This vulnerability, CVE-2026-15972, is fixed in Consul 2.0.3 and Consul Enterprise 1.21.17, 1.22.11, and 2.0.3.

Why

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

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
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

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 → Allocation of Resources Without Limits or Throttling → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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-770 ↗

CWE-770: Allocation of Resources Without Limits or Throttling. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

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:N/UI:N/S:U/C:N/I:N/A:H

Common 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.PRNonePrivileges required: The attacker does not need an account or existing 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.
NetworkUnauthenticatedDenial of serviceCWE-770
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

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
1.13.0 < 2.0.3
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 7 Aug 2026 · Last source change 10 Aug 2026, 18:24 UTC · CWE-770 · Allocation of Resources Without Limits or Throttling

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-54612
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-54612↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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.
Free version - for non-commercial use only.CVE-2026-15972 · cve.blacktree.nl