Vulnerability advisory

EEF-CVE-2026-48596

CRLF injection in Tesla.Multipart.add_content_type_param/2 allows HTTP header injection

Published Jun 2, 2026Updated Sep 24, 2026OSV record ↗

Also known as CVE-2026-48596GHSA-q7jx-v53g-848w

Severity

CVSS 4.0CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

Affected versions

tesla Hex

All tesla advisories →

Affected Fixed in

0.8.0 to before 1.18.3 1.18.3Advisories →

Affected	Fixed in
`0.8.0` to before 1.18.3	`1.18.3`Advisories →
Also listed as affected (52) `0.10.0` `0.8.0` `0.9.0` `1.0.0` `1.0.0-beta.1` `1.1.0` `1.10.0` `1.10.1` `1.10.2` `1.10.3` `1.11.0` `1.11.1` `1.11.2` `1.12.0` `1.12.1` `1.12.2` `1.12.3` `1.13.0` `1.13.1` `1.13.2` `1.14.0` `1.14.1` `1.14.2` `1.14.3` `1.15.0` `1.15.1` `1.15.2` `1.15.3` `1.16.0` `1.17.0` `1.18.0` `1.18.1` `1.18.2` `1.2.0` `1.2.1` `1.3.0` `1.3.1` `1.3.2` `1.3.3` `1.4.0` `1.4.1` `1.4.2` `1.4.3` `1.4.4` `1.5.0` `1.5.1` `1.6.0` `1.6.1` `1.7.0` `1.8.0` `1.8.1` `1.9.0`

Also listed as affected (52)

Repository

Affected commits	Fixed by commit
GIT github.com/elixir-tesla/tesla ↗
6ebfdb9abe9c6f119408045b933d82462decd351 to before 23601edac5d22ba9407b427967b5bdbda201aec2	`23601edac5d22ba9407b427967b5bdbda201aec2`

Description

Summary

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. Any application that forwards untrusted input (such as a user-supplied charset or parameter string) into add_content_type_param/2 is affected.

This issue affects tesla: from 0.8.0 before 1.18.3.

Workarounds

Validate content-type parameter strings before passing them to Tesla.Multipart.add_content_type_param/2, rejecting any value that contains \r or \n.

Configurations

The application must pass untrusted input into Tesla.Multipart.add_content_type_param/2.