Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:NSummary
CVE-2026-42038 is a medium-severity SSRF (CWE-918) vulnerability in Axios Axios. Its CVSS base score is 6.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 23th 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 AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — 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-2026-42038 affects Axios, a promise-based HTTP client used in browsers and Node.js environments. In versions prior to 1.15.1 and 0.31.1, an incomplete fix for no_proxy hostname normalization allows a bypass. Specifically, when no_proxy is set to "localhost," requests to 127.0.0.1 and [::1] are not bypassed and continue routing through the proxy. This stems from the shouldBypassProxy() function performing pure string matching without resolving IP aliases or loopback equivalents. The vulnerability carries a CVSS v3.1 base score of 6.8 (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N) and is associated with CWE-918 (Server-Side Request Forgery).
Attackers can exploit this vulnerability remotely with no privileges or user interaction required, though it demands high attack complexity and a changed scope. Exploitation is feasible in scenarios where an application uses Axios with a no_proxy setting for localhost but issues requests to loopback addresses like 127.0.0.1 or [::1]. A malicious actor controlling or monitoring the proxy can intercept these requests, potentially accessing sensitive data in transit and achieving high confidentiality impact without affecting integrity or availability.
The GitHub security advisory (GHSA-m7pr-hjqh-92cm) confirms the issue and states that it is fixed in Axios versions 1.15.1 and 0.31.1. Practitioners should upgrade to these patched releases to mitigate the vulnerability by ensuring proper proxy bypass logic for loopback equivalents.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-25604
Vulnerability Data
Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, he fix for no_proxy hostname normalization bypass is incomplete. When no_proxy=localhost is set, requests to 127.0.0.1 and [::1] still route through the proxy…
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instead of bypassing it. The shouldBypassProxy() function does pure string matching — it does not resolve IP aliases or loopback equivalents. 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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V1.3.6V1.5.3V5.3.2V10.4.7
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
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 development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
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.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.