Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-reachable with no auth needed, but AC:H reflects AT:P partial-control constraint; availability-only low impact from worker restart, no scope change.
Primary rating from Vendor (f5).
CVSS VectorVendor: f5
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
4DescriptionCVE.org
When NGINX Plus is configured to use the Message Queuing Telemetry Transport (MQTT) filter module (ngx_stream_mqtt_filter_module), unauthenticated attackers can send requests with conditions beyond the attacker's control to cause a heap buffer over-read in the NGINX worker process, leading to a restart.
Impact: This vulnerability may allow remote unauthenticated attackers to have limited control to restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AnalysisAI
Heap buffer over-read in NGINX Plus's MQTT filter module (ngx_stream_mqtt_filter_module) allows unauthenticated remote attackers to crash the NGINX worker process, causing a brief, recoverable service disruption. The vulnerability is data-plane only - no control plane exposure exists - and exploitation depends partly on runtime conditions outside the attacker's control, reflected by the CVSS 4.0 AT:P metric. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires NGINX Plus to be explicitly configured with the ngx_stream_mqtt_filter_module in a stream block - this is a non-default, operator opt-in configuration absent from standard NGINX Plus deployments. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The vendor-assigned CVSS 4.0 score of 6.3 reflects a moderate, availability-only risk profile. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An unauthenticated attacker who has network access to an NGINX Plus instance with the MQTT filter module enabled sends a specially crafted MQTT protocol message to the stream listener port. Under specific runtime conditions that the attacker cannot fully control, the malformed message triggers a heap buffer over-read in the NGINX worker process, causing it to crash and restart - interrupting active MQTT connections for the duration of the respawn cycle. … |
| Remediation | Apply the vendor-released patch by upgrading to the fixed NGINX Plus version specified in F5 advisory K000162101 (https://my.f5.com/manage/s/article/K000162101); the advisory provides exact version targets and upgrade procedures. … Detailed patch versions, workarounds, and compensating controls in full report. |
Threat intelligence, references, and detailed analysis are available after sign-in.
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-44685
GHSA-w94h-5qpm-994v