Axios EUVD-2026-88371

Exploitation is only possible when THREE conditions coincide: (1) the application uses the Axios default instance and issues requests that OMIT an explicit method - e.g. axios({ url }) or axios.request({ url }) - so the method falls back to a default; (2) a SEPARATE prototype-pollution vulnerability exists elsewhere in the same Node.js process and has planted a value on Object.prototype.method; and (3) the Axios version is in the affected range (0.27.2 to <0.34.0, or 1.0.0 to <1.20.0). Axios itself does not create the pollution source, so this gadget is completely inert without the chained pollution primitive - that dependency is the primary limiting factor and the reason the AT:P (attack-requirement) flag is set. Calls that pass an explicit method are unaffected.

The vendor CVSS 4.0 vector (AV:N/AC:L/AT:P/PR:N/UI:N) with SI:H as the only non-zero impact frames this as a network-reachable, unauthenticated integrity issue, scoring 6.9. That score materially overstates standalone risk: the AT:P (Attack Requirements: Present) flag and the description itself make clear this is a READ-SIDE GADGET, not a self-contained vulnerability. Axios does not create the prototype-pollution source - exploitation is inert unless a SEPARATE flaw in the same Node.js process already pollutes Object.prototype.method. My independent assessment therefore rates attack complexity as high (AC:H), which no raw signal in the input captures. No EPSS score, no CISA KEV listing, and no public POC are provided, so all exploitation-likelihood signals are absent or neutral. This is a defense-in-depth hardening fix in an ubiquitous library rather than a directly actionable high-priority vulnerability: real priority is LOW-to-MEDIUM, driven almost entirely by Axios's enormous deployment footprint, not by standalone exploitability. Note the tag 'Information Disclosure' conflicts with the vector, which encodes integrity (SI:H, all confidentiality metrics N) - the impact is method substitution, not data leakage.

In a Node.js service that already contains a prototype-pollution vulnerability, an attacker pollutes Object.prototype.method with a state-changing verb (e.g. DELETE or POST). A subsequent default-instance call such as axios.request({ url }) or axios({ url }), which omits an explicit method and would normally default to GET, instead inherits the polluted value and dispatches the unexpected verb - potentially converting a benign read into a state-changing operation against the target. No public exploit code is identified for this gadget in isolation, and it cannot be triggered without the separate pollution primitive.