Critical Axios Vulnerability Enables Full Cloud Infrastructure Compromise

A severe security flaw has been identified in Axios, one of the internet’s most popular HTTP client libraries. This vulnerability (CVE-2026-40175) allows Remote Code Execution (RCE) and complete cloud infrastructure compromise by bypassing critical security controls. With a critical CVSS 3.1 score of 9.9, attackers can exfiltrate sensitive cloud metadata and escalate privileges in affected systems.

Exploit Chain: Prototype Pollution & HTTP Smuggling

The vulnerability stems from a chain of security weaknesses in Axios:

• Unrestricted Header Injection: Flawed processing in lib/adapters/http.js lacks HTTP header sanitization (CWE-113)
• Default SSRF Functionality: Built-in Server-Side Request Forgery capabilities (CWE-918)
• Gadget Chain Attack: Exploits prototype pollution via other dependencies like body-parser, qs, or minimist

When attackers pollute Object.prototype through compromised dependencies, Axios automatically merges these malicious properties during configuration. The library’s failure to sanitize Carriage Return Line Feed (CRLF) characters transforms these properties into HTTP smuggling payloads. This “zero-input” attack requires no direct user interaction to trigger catastrophic consequences.

AWS IMDSv2 Bypass and Cloud Takeover

Public Proof-of-Concept (PoC) code demonstrates how this vulnerability enables cloud infrastructure compromise. Attackers smuggle PUT requests to the AWS EC2 Metadata Service (169.254.169.254) by injecting headers like x-amz-target. This bypasses IMDSv2’s X-aws-ec2-metadata-token-ttl-seconds protection, allowing attackers to:

• Steal IAM credentials
• Execute arbitrary commands
• Poison authentication systems
• Compromise cloud resources

More technical details are available in the official Axios advisory and researcher jasonsaayman‘s disclosure.

Affected Versions: All Axios versions prior to 1.15.0 are vulnerable. See full details in full disclosure.

Immediate Actions:

1. Update Immediately: Patch to Axios 1.15.0 or later
2. Critical Patch Details: Version 1.15.0 enforces strict CRLF validation in headers, triggering security errors on malicious inputs
3. Secondary Protection: Audit all dependencies for prototype pollution vulnerabilities

The patched version prevents header injection by validating all input values before processing. Organizations must test updates in staging environments before deployment to mission-critical systems.