Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
PR:L reflects the mTLS certificate requirement; AC:L because exploitation is deterministic once credentials are held; C:N/I:N as only server availability is impacted.
Primary rating from Vendor (HashiCorp).
CVSS VectorVendor: HashiCorp
Lifecycle Timeline
3DescriptionCVE.org
Consul and Consul Enterprise are vulnerable to a denial of service in the native RPC listener that may allow an authenticated client to exhaust server memory before ACL authorization is evaluated. A client that can complete the internal RPC mTLS handshake may exploit this issue without holding a valid ACL token. This vulnerability (CVE-2026-87106) is fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12 and 2.0.4.
AnalysisAI
Memory exhaustion denial of service in HashiCorp Consul's native RPC listener allows a network-adjacent client holding a valid mTLS certificate - but no ACL token - to crash or severely degrade Consul servers by exhausting server memory before ACL authorization is evaluated. Both open-source Consul and Consul Enterprise are affected across multiple release tracks. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the attacker to hold a valid TLS client certificate trusted by the target Consul cluster's CA - sufficient to complete the internal RPC mTLS handshake - and network-level reachability to the native RPC listener (default TCP port 8300). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 6.5 score with vector AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H accurately reflects the nature of this issue: network-accessible, low-complexity, requiring only low-level credentials (valid mTLS client certificate), with purely availability impact. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Upgrade Consul open-source to version 2.0.4 or Consul Enterprise to 1.21.18, 1.22.12, or 2.0.4 depending on your release track, as documented in HashiCorp advisory HCSEC-2026-35 (https://discuss.hashicorp.com/t/hcsec-2026-35-consul-vulnerable-to-a-denial-of-service-in-the-native-rpc-listener/77737). … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-75680
GHSA-q5mw-fjrj-6qmh