CVE-2026-48595
MediumCVSS 5.9Exploitation Probability (EPSS)
Low risk40th percentile - higher than 40% of all known CVEs
Summary
Tesla library (Elixir) versions from 1.4.0 before 1.18.3 improperly handle case sensitivity in HTTP headers during cross-origin redirects. The Authorization header in canonical form (e.g., "Authorization") is not filtered, leading to credential leakage to a third-party origin.
Risk Assessment
Leakage of Bearer tokens or other credentials to a third-party origin could allow an attacker to hijack user accounts or access protected resources.
Recommendation
Update the Tesla library to version 1.18.3 or later.
Other vulnerabilities in Tesla
See all- CVE-2026-48597Medium
Resource exhaustion vulnerability in the Tesla library (Elixir) before version 1.18.3. Tesla.Adapter.Mint.open_conn/2 converts the URL scheme of every request to a BEAM atom without validation, potentially filling the atom table and crashing the VM. An attacker can influence the request URL via redirect features or webhooks.
- CVE-2026-48596Low
Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') vulnerability in elixir-tesla tesla allows HTTP header injection via Tesla.Multipart.add_content_type_param/2. Tesla.Multipart.add_content_type_param/2 appends caller-supplied strings to the multipart content_type_params list without validating for CR (\r) or LF (\n) characters. Tesla.Multipart.headers/1 then joins these params verbatim with "; " to construct the outgoing Content-Type header value. A param containing \r\n splits the header line, allowing arbitrary headers to be injected into the outbound HTTP request.
- CVE-2026-48594High
Vulnerability in the Tesla library for Elixir (versions 0.6.0 up to before 1.18.3) due to improper handling of highly compressed data (decompression bomb). HTTP responses are decompressed without size limits, and multiple compression layers can lead to exponential data expansion, causing memory exhaustion and denial of service.
Original NVD description (English source)
Improper Handling of Case Sensitivity vulnerability in elixir-tesla tesla allows credential leakage to a third-party origin on cross-origin redirects. Tesla.Middleware.FollowRedirects strips security-sensitive headers on cross-origin redirects using a case-sensitive string comparison against a lowercase filter list (@filter_headers ["authorization", "host"]). HTTP header names are case-insensitive per RFC 7230, but Tesla preserves header keys verbatim as supplied by the caller without normalizing case. A header set as {"Authorization", "Bearer …"} (the RFC 7235 canonical casing used by virtually all HTTP libraries and documentation) does not match the lowercase filter entry and is forwarded to the redirect destination. An attacker who can control or influence a Location: response seen by the client (via their own endpoint, a redirect-open upstream, or a compromised origin) receives the bearer token or other Authorization material on the cross-origin request. This issue affects tesla: from 1.4.0 before 1.18.3.