CVE-2026-42035
Axios ≤ 0.31.1
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NSummary
CVE-2026-42035 is a high-severity HTTP Request/Response Splitting (CWE-113) vulnerability in Axios Axios. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-42035 is a prototype pollution vulnerability in the Axios HTTP client library for browsers and Node.js, specifically within the HTTP adapter at lib/adapters/http.js. Versions prior to 1.15.1 and 0.31.1 are affected, where duck-type checking of data payloads can be exploited. If Object.prototype is polluted with methods such as getHeaders, append, pipe, on, once, and Symbol.toStringTag, Axios incorrectly identifies a plain object as a FormData instance and invokes the attacker-controlled getHeaders() function, allowing arbitrary HTTP headers to be merged into outgoing requests. The pollution source can originate from any dependency in the application's tree, not necessarily Axios itself.
A remote attacker with no privileges can exploit this by triggering prototype pollution through a vulnerable dependency, enabling injection of arbitrary headers into Axios-generated HTTP requests. This misidentification occurs during payload processing, compromising confidentiality and integrity (CVSS 7.4: AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) without impacting availability. Exploitation requires high attack complexity, typically involving a chain from an initial prototype pollution primitive to Axios usage with a crafted plain object payload.
The GitHub security advisory (GHSA-6chq-wfr3-2hj9) confirms the issue is resolved in Axios versions 1.15.1 and 0.31.1, recommending immediate upgrades for affected installations. Practitioners should audit dependencies for prototype pollution risks and monitor for vulnerable Axios versions in browser and Node.js environments.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-25589
Vulnerability Data
Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, a prototype pollution gadget exists in the Axios HTTP adapter (lib/adapters/http.js) that allows an attacker to inject arbitrary HTTP headers into outgoing requests.…
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The vulnerability exploits duck-type checking of the data payload, where if Object.prototype is polluted with getHeaders, append, pipe, on, once, and Symbol.toStringTag, Axios misidentifies any plain object payload as a FormData instance and calls the attacker-controlled getHeaders() function, merging the returned headers into the outgoing request. The vulnerable code resides exclusively in lib/adapters/http.js. The prototype pollution source does not need to originate from Axios itself — any prototype pollution primitive in any dependency in the application's dependency tree is sufficient to trigger this gadget. This vulnerability is fixed in 1.15.1 and 0.31.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.4.2V4.1.3V1.3.6V4.2.3
Mitigating Controls (NIST 800-53 r5) AI
Input validation stops unneutralized CR/LF characters from being accepted and later emitted in HTTP headers.
Output filtering can neutralize CRLF sequences before they reach HTTP response headers.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input sanitization and header handling that prevent CRLF injection.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance can detect CRLF injection flaws before deployment.
Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection into HTTP headers.
Application security requirements explicitly call for controls against injection flaws including HTTP header manipulation.
Secure architecture principles reduce the likelihood of header-splitting vulnerabilities through proper component isolation.
Secure coding standards require neutralization of CRLF sequences before inclusion in HTTP headers.
Change-management processes ensure security fixes for prototype-pollution issues are tracked and deployed.