CVE-2026-42040

A flaw was found in Axios, a software component used for making web requests. This vulnerability allows for the incorrect handling of null bytes, where a safely encoded null byte (%00) is converted back to its raw form (\x00). While the standard use of Axios is not affected, this could lead to unexpected data processing or integrity issues in certain specialized applications. The overall impact of this flaw is considered limited.

Red Hat rates this vulnerability as Low impact with a CVSS score of 3.7, matching the upstream assessment. The vulnerable code only runs when URL search parameters are built through the AxiosURLSearchParams helper. Standard axios request methods (get, post, etc.) do not use this helper, and Red Hat products that bundle axios construct HTTP parameters from trusted internal inputs rather than unsanitized user data. For exploitation, an attacker would need to inject null bytes into user input that reaches this specific helper, which is unlikely in typical deployments. If a raw null byte reaches a downstream system that treats it as a string terminator, it could cause unexpected behavior such as parameter truncation, path traversal, or security filter bypass. The practical risk remains low because exploitation requires both unsanitized user input flowing into the AxiosURLSearchParams helper and a backend that interprets null bytes differently from the sending application.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Validate and sanitize user-controlled input to remove null bytes before passing it to URL parameter construction. Standard axios request methods (axios.get, axios.post with a params object) do not use the vulnerable AxiosURLSearchParams helper and are not affected.