Axios CVE-2026-40175 Vulnerability: Risks for AWS

Critical Axios Vulnerability Threatens Cloud Infrastructures via Attack Chain

Axios versions prior to 1.15.0 contain a critical vulnerability, CVE-2026-40175, allowing attackers to achieve remote code execution and compromise AWS resources through prototype pollution. Public proof-of-concept (PoC) exploits are already available, and a patch has been released — immediate updates are essential for all users.

Exploitation Mechanism and Risks

The vulnerability stems from insufficient validation of CR and LF characters in the AxiosHeaders.set method. This enables CRLF injection when polluted Object prototype properties are passed into HTTP headers without filtering.

The attack chain typically begins with compromising dependencies such as qs, minimist, or body-parser. Once Object.prototype is polluted, Axios inherits these tainted properties, leading to malicious header injection and HTTP request splitting. As a result, attackers can access the AWS Instance Metadata Service at 169.254.169.254.

Impact on cloud environments:

• Retrieval of temporary IAM tokens via PUT requests.
• Privilege escalation across infrastructure.
• Full compromise of microservices and containers.

The vulnerability is widespread: approximately 39% of 20,000 active hosts scanned in the Russian-speaking internet are vulnerable, with the real number likely higher due to hidden usage within backend services.

Indicators of Compromise

Monitoring logs can help detect attacks early. Key red flags include:

• Abnormal PUT requests targeting 169.254.169.254.
• Manipulation of __proto__ or constructor.prototype in headers.
• Presence of CRLF sequences like %0d%0a or \r\n in requests.
• Unauthorized use of IAM tokens from unexpected IP addresses.
• Header parsing errors and HTTP 500 responses in Node.js applications.

Mitigation Measures and Context

Prototype Pollution is a well-known technique that exploits JavaScript’s dynamic nature. In the npm ecosystem, vulnerabilities in widely used libraries like Axios (with over 60 million weekly downloads) pose systemic risks to millions of applications.

Root causes: Lack of strict input validation for HTTP headers. This reflects broader software supply chain challenges where third-party dependencies propagate silently.

Industry impact: A CVSS 3.1 score of 9.9–10.0 highlights the severity for cloud providers. Past incidents like Log4Shell demonstrated how local flaws can escalate into global threats.

Recommended actions:

• Immediately upgrade to Axios 1.15.0, which includes assertValidHeaderValue checks.
• Audit dependencies using npm audit and SCA tools.
• Restrict access to IMDS using network policies and Security Groups.
• Configure WAF rules to block suspicious patterns.

Key Takeaways

• The flaw enables RCE via Prototype Pollution and CRLF injection, directly endangering AWS workloads.
• Affects all versions below 1.15.0; public PoCs have been available since April 10, 2026.
• 39% of scanned hosts remain exposed — underestimating risk is dangerous.
• Patching is available but requires full dependency chain verification.
• Broader implication: reinforces the need for zero-trust architectures in cloud environments.

— Editorial Team