Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach ts_lua-enabled ATS proxy
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DeliverySend crafted HTTP requests
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ExploitTrigger mishandled transform/per-instance state
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ExecutionDrive uncontrolled resource consumption
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ImpactCrash or hang proxy (DoS)
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource consumption limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires that the target Apache Traffic Server instance has the ts_lua plugin loaded and active (configured via plugin.config or per-remap in remap.config) - proxies without ts_lua are not affected. No authentication is required (PR:N) and no user interaction is needed (UI:N), and the proxy must be network-reachable by the attacker (AV:N). The defining limiter is the CVSS 4.0 AT:P (attack requirement present): a specific condition beyond the attacker's control - tied to the plugin's initialization, transform context, or per-instance state handling - must hold for the resource-consumption path to trigger, which is why this is not a trivially reliable remote crash against every Lua-enabled deployment. Impact is limited to availability (VA:H, with VC:N/VI:N). |
| Impact | The signals are internally consistent but point to a moderate, not top-tier, real-world priority. The CVSS 4.0 vector (AV:N/AC:L/AT:P/PR:N/UI:N, VA:H, all confidentiality and integrity impact N) confirms a network-reachable, unauthenticated, availability-only issue - no data disclosure or code execution. The base score of 8.2 is driven largely by the network vector and high availability impact, but the AT:P (attack requirement present) metric explicitly tempers it: successful exploitation depends on a condition the attacker does not fully control, which is why the score is not higher. No EPSS value was provided, it is not in CISA KEV (no confirmed active exploitation), and no POC was supplied, so exploitation is unproven. The single largest limiting factor is that ts_lua is an optional plugin - environments not running Lua scripting are not exposed at all. Bottom line: a genuine uptime/DoS concern for ATS fleets that use ts_lua, but not an emergency for the broader ATS install base, and clearly not a confidentiality/integrity breach. |
| Exploit ScenarioDerived | An attacker who can send HTTP requests to an internet-facing ATS proxy that has the ts_lua plugin enabled repeatedly triggers the mishandled transform/per-instance state path, causing the proxy to leak or exhaust resources until it crashes or stops serving traffic. Because the CVSS attack requirement is Present (AT:P), the attacker needs the right condition to be met - such as a specific ts_lua hook or transform being configured - rather than any arbitrary request. No public exploit code is identified at time of analysis. |
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Alert meAnalysisAIv2 – Jul 29, 2026
Denial of service in Apache Traffic Server (versions 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3) arises from the ts_lua plugin mishandling initialization, transform context, and per-instance state, allowing remote unauthenticated attackers to exhaust or corrupt resource state and crash or hang the proxy (CVSS 4.0 base 8.2, availability-only impact). Exploitation carries an attack requirement (AT:P), meaning a specific condition beyond the attacker's control must hold, and only deployments that actually load the ts_lua scripting plugin are affected. There is no public exploit identified at time of analysis and it is not listed in CISA KEV; treat it as a serviceability/uptime risk to Lua-enabled ATS proxies.
Earlier versions of this analysis (1)
Resource exhaustion in Apache Traffic Server's ts_lua plugin - spanning versions 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3 - exposes internet-facing deployments to unauthenticated denial of service with secondary confidentiality and integrity impact. The root cause is improper handling of plugin initialization, transform context, and per-instance state (CWE-400), all reachable without credentials or user interaction per the AV:N/PR:N/UI:N CVSS vector. No public exploit or CISA KEV listing has been identified at time of analysis, but the vendor has confirmed the flaw and released fixes in 9.2.15 and 10.1.4.
RemediationAI
Vendor-released patch: upgrade to Apache Traffic Server 9.2.15 (for the 9.x line) or 10.1.4 (for the 10.x line), per the Apache advisory at https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d; note that the 8.x line (8.0.0-8.1.9) is listed as affected but no fixed 8.x release is named, so 8.x operators should plan a migration to a patched 9.2.15+ or 10.1.4+ release. If patching cannot be done immediately, the most direct compensating control is to disable or unload the ts_lua plugin (remove its plugin.config / remap.config entries), which fully removes the exposure at the cost of losing any Lua-based request/response scripting your configuration relies on. Where ts_lua must stay enabled, restrict who can reach the affected proxy paths and put rate-limiting or an upstream WAF/load balancer in front of the ATS tier to blunt resource-exhaustion attempts, accepting that this mitigates rather than eliminates the DoS risk.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Apache Traffic Server is a high-performance, event-driven forward and reverse caching HTTP proxy widely used as a CDN edge and origin-shield layer. The ts_lua plugin embeds a LuaJIT/Lua scripting engine so operators can attach per-request hooks, response/request transforms, and per-instance configuration to the proxy pipeline. The flaw is rooted in CWE-400 (Uncontrolled Resource Consumption): the plugin mismanages its lifecycle state - specifically initialization sequencing, the transform context used for streaming body rewrites, and per-instance state isolation. When these states are mishandled, resources tied to Lua VM contexts or transform buffers are not correctly bounded or released, letting an attacker drive the process toward resource exhaustion or an inconsistent-state crash. The CPE covers cpe:2.3:a:apache_software_foundation:apache_traffic_server across all listed versions, but the defect lives in the optional ts_lua plugin rather than the core proxy.
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Remote and unauthenticated (AV:N/PR:N) but the AT:P precondition and ts_lua-only exposure map to AC:H; impact is availability-only (A:H, C/I:N).
Primary rating from Vendor (apache).
CVSS VectorVendor: apache
Lifecycle Timeline
4DescriptionCVE.org
The Apache Traffic Server ts_lua plugin mishandles initialization, transform context, and per-instance state.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3.
Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Executive ViewAI
Apache Traffic Server versions 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3 with the ts_lua plugin enabled are vulnerable to remote denial-of-service attacks that crash or hang the proxy, directly disrupting traffic management and service availability for dependent applications. Organizations running these versions face potential unexpected service outages and operational impact. Immediate remediation through plugin disablement or version upgrades is required.
Disable the ts_lua plugin immediately if not required for production functionality to eliminate this attack vector. Restrict network access to the Apache Traffic Server proxy through firewall rules and network segmentation to limit attacker reach. Deploy monitoring on proxy resource metrics (CPU, memory, active connections) to detect exploitation attempts via resource exhaustion. No vendor-released patch identified at time of analysis; upgrade to patched versions remains the primary remediation path.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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EUVD-2026-50227
GHSA-x56q-2cqh-7326
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB