Weakness Type (CWE)

CWE-113 — CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

CAPEC

CVSS 4.0 Score

2.1

LOW

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

Vulnerability description

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.

Affected

pkg:hex/tesla

Module Source File Routine
Tesla.Multipart lib/tesla/multipart.ex Tesla.Multipart.add_content_type_param/2
Tesla.Multipart.headers/1
Status Type Version Changes / Fixed in
affected semver ⓘ 0.8.0 < 1.18.3

pkg:github/elixir-tesla/tesla

Module Source File Routine
Tesla.Multipart lib/tesla/multipart.ex Tesla.Multipart.add_content_type_param/2
Tesla.Multipart.headers/1
Status Type Version Changes / Fixed in
affected git ⓘ 6ebfdb9abe < 23601edac5

Configurations

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

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.

References

Credits

  • Finder: Peter Ullrich
  • Remediation developer: Yordis Prieto
  • Analyst: Jonatan Männchen

CVE record as JSON:  GET /cves/CVE-2026-48596.json
OSV record as JSON:  GET /osv/EEF-CVE-2026-48596.json