Elixir Tesla CVE-2026-48597

The target application must depend on tesla between 1.3.0 and 1.18.2 and must be configured to use Tesla.Adapter.Mint specifically; other Tesla adapters do not call String.to_atom on the URL scheme. The attacker must also be able to influence the scheme portion of a URL that the application passes to Tesla - typically through an application-level URL-forwarding feature such as a webhook sender, outbound proxy, link previewer, or content importer, or indirectly by getting Tesla.Middleware.FollowRedirects to chase a Location header containing an attacker-chosen scheme. No authentication, user interaction, or local access is required (CVSS PR:N/UI:N/AV:N), but the CVSS AT:P attack-requirement reflects the need for this URL-influence channel; deployments that only contact a hard-coded set of internal URLs, or that strictly allow-list schemes upstream of Tesla, are not exploitable. The attacker must also be able to send on the order of one million requests to fully exhaust the default 1,048,576-entry atom table, although operational impact (memory growth, slower atom lookups) begins well before total exhaustion.

The CVSS 4.0 vector AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H scores 8.2 (High) and accurately reflects the threat shape: network-reachable, low complexity, no privileges or user interaction, but with an attack-requirement (AT:P) reflecting that the attacker needs to influence the URL scheme - typically through a webhook/proxy/importer feature or a malicious Location header combined with Tesla.Middleware.FollowRedirects. Impact is confined to availability (VA:H) with no confidentiality or integrity loss, but a BEAM crash takes the entire application down, not just a single request. There is no EPSS score or CISA KEV entry provided in the input, and no public exploit identified at time of analysis; however, the GitHub Security Advisory (GHSA-h74c-q9j7-mpcm) and the patch commit clearly disclose the trigger, so weaponization is trivial for any attacker who can find an HTTP-forwarding feature backed by Tesla.Adapter.Mint. Real-world priority is highest for applications that either accept user-supplied URLs (webhook senders, link previewers, importers, SSRF-prone features) or that enable Tesla.Middleware.FollowRedirects against untrusted hosts; deployments using other Tesla adapters (Hackney, Finch, Gun) are not affected by this specific code path.

An Elixir web service exposes a webhook-test or URL-import feature that forwards user-supplied URLs through Tesla configured with the Mint adapter. The attacker submits a stream of requests whose URLs use unique, randomly generated schemes (for example atk-1://victim, atk-2://victim, …), and after roughly one million such requests - or fewer if combined with FollowRedirects bouncing to attacker-controlled servers that return Location headers with novel schemes - the BEAM atom table fills and the entire VM crashes, taking the application offline. No public exploit identified at time of analysis, but the public patch diff and accompanying regression test that calls call(%Env{url: "atk-...://127.0.0.1/"}) effectively document the trigger.