CVE-2026-42044 Axios: Invisible JSON Response Tampering via Prototype Pollution Gadget in `parseReviver`
Prototype pollution allows attackers to tamper with JSON API responses via a polluted parseReviver function, enabling data manipulation and privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42044?
CVE-2026-42044 is a medium-severity unsafe deserialization vulnerability in axios, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Axios is a promise based HTTP client for the browser and Node.js. From 1.0.0 to before 1.15.2, he Axios library is vulnerable to a Prototype Pollution "Gadget" attack that allows any Object.prototype pollution in the application's dependency tree to be escalated into surgical, invisible modification of all JSON API responses — including privilege escalation, balance manipulation, and authorization bypass. The default transformResponse function at lib/defaults/index.js:124 calls JSON.parse(data, this.parseReviver), where this is the merged config object. Because parseReviver is not present in Axios defaults, not validated by assertOptions, and not subject to any constraints, a polluted Object.prototype.parseReviver function is called for every key-value pair in every JSON response, allowing the attacker to selectively modify individual values while leaving the rest of the response intact. This vulnerability is fixed in 1.15.2.
Which versions are affected by CVE-2026-42044?
2 open source packages ship an affected version, including axios. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
axios npm | From 1.0.0 | 1.15.2 |
axios npm | From 1.0.0 | 1.15.2 |
Products include Axios Axios.
How do I fix CVE-2026-42044?
Upgrade axios to 1.15.2 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-42044 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42044 exists.
Other vulnerabilities in axios
- CVE-2026-44494 Axios: Full Man-in-the-Middle via Prototype Pollution Gadget in `config.proxy`
- CVE-2026-44492 axios's shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718)
- CVE-2026-67320 axios before 0.33.0 Prototype Pollution via Node HTTP adapter
- CVE-2026-44487 Axios: Proxy-Authorization Credential Leak to Origin Server Across HTTP-to-HTTPS Redirect in Axios Node.js HTTP Adapter
- CVE-2025-27152 Possible SSRF and Credential Leakage via Absolute URL in axios Requests
Sources
Also known as CLEANSTART-2026-KS96155, CLEANSTART-2026-ZL88777, DEBIAN-CVE-2026-42044, ECHO-c119-30b2-6b3d, GHSA-3w6x-2g7m-8v23, MINI-2ppr-gvg9-p8g3 and 22 more.