CVE-2026-48595

Published Jun 2, 2026 Modified Jun 4, 2026 CWE-178

Description

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.

EPSS — Exploit Prediction

0.0040
Probability of exploitation
0.32%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-178 CWE-178

References

Frequently Asked Questions

What is CVE-2026-48595? +
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.
How do I check if I'm vulnerable to CVE-2026-48595? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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