EEF-CVE-2026-48595

Source
https://cna.erlef.org/osv/EEF-CVE-2026-48595.html
Import Source
https://cna.erlef.org/osv/EEF-CVE-2026-48595.json
JSON Data
https://api.osv.dev/v1/vulns/EEF-CVE-2026-48595
Aliases
  • CVE-2026-48595
  • GHSA-9m9w-gxf7-rh8m
Published
2026-06-02T19:08:48.339Z
Modified
2026-06-04T04:45:31.067Z
Severity
  • 8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Authorization header leaks to third-party origin on cross-origin redirect in Tesla.Middleware.FollowRedirects
Details

Summary

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.

Workaround

Normalize all header keys to lowercase before passing them to Tesla. Use "authorization" instead of "Authorization" when setting headers via Tesla.put_header/3 or Tesla.Middleware.Headers.

Configuration

The application must include Tesla.Middleware.FollowRedirects in its Tesla middleware pipeline.

Database specific
{
    "cwe_ids": [
        "CWE-178"
    ],
    "cpe_ids": [
        "cpe:2.3:a:elixir-tesla:tesla:*:*:*:*:*:*:*:*"
    ],
    "capec_ids": [
        "CAPEC-267"
    ]
}
References
Credits
    • Peter Ullrich - FINDER
    • Yordis Prieto - REMEDIATION_DEVELOPER
    • Jonatan Männchen - ANALYST

Affected packages

Hex / tesla

Package

Name
tesla
Purl
pkg:hex/tesla

Affected ranges

Type
SEMVER
Events
Introduced
1.4.0
Fixed
1.18.3

Affected versions

1.*
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
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

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-48595.json"

Git / github.com/elixir-tesla/tesla.git

Affected ranges

Type
GIT
Repo
https://github.com/elixir-tesla/tesla.git
Events

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-48595.json"