How severe is CVE-2026-48595?

No CVSS score has been assigned to CVE-2026-48595 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-48595?

CVE-2026-48595 affects the following packages: tesla (Hex). Ecosystems affected: Hex.

How do I fix CVE-2026-48595?

Update tesla to 1.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48595 is resolved across your whole dependency graph.

How do I detect CVE-2026-48595 in my Hex dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tesla, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-48595 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-48595 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-48595 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-48595?

CVE-2026-48595 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 50th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-48595?

CVE-2026-48595 is classified as CWE-178 (CWE-178). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-48595 published, and has it been updated?

CVE-2026-48595 was published on June 2, 2026 and was last updated on September 26, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

Not in CISA KEV

CVE-2026-48595 — tesla

Fix: elixir-tesla/tesla@2d937d5

CVE-2026-48595 is a CWE-178 vulnerability in tesla. A fix is available for tesla — see the affected versions and patch details below.

Authorization header leaks to third-party origin on cross-origin redirect in Tesla.Middleware.FollowRedirects

Also known asEEF-CVE-2026-48595GHSA-9m9w-gxf7-rh8m

Published

Jun 2, 2026

Updated

Sep 26, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-48595.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs50th percentile — riskier than 50% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

💧tesla

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Tesla.Middleware.FollowRedirects is meant to strip the Authorization header when following a cross-origin redirect, but performs the check with a case-sensitive comparison against the lowercase string "authorization". Because Tesla preserves header keys exactly as supplied by the caller, any application that sets the header with its RFC 7235 canonical casing ("Authorization") bypasses the filter entirely, leaking bearer tokens or other credentials to whatever origin the redirect points at.

Details

The filter list in lib/tesla/middleware/follow_redirects.ex is defined as @filter_headers ["authorization", "host"] and the membership check k not in @filter_headers compares the raw key string without case normalization. HTTP header names are case-insensitive per RFC 7230, but Tesla stores them verbatim. A header tuple {"Authorization", "Bearer …"} does not match "authorization", so it passes through the filter and is forwarded to the redirect destination unchecked. The same defect applies to the "Host" entry.

An attacker who can control a Location: response seen by the victim client (their own endpoint, a redirect-open service, or a compromised upstream) receives the credential on the cross-origin follow. No special configuration is required beyond the victim using the standard header casing.

PoC

Configure a Tesla client with Tesla.Middleware.FollowRedirects and set the Authorization header using canonical casing ({"Authorization", "Bearer <token>"}).
Make a request to an endpoint that returns a 302 redirect to a different origin.
Observe that the Authorization header with its value is present in the request delivered to the redirect destination.

Impact

High severity (CVSS v4.0: 8.2). Any application using tesla 1.4.0 through 1.18.2 with Tesla.Middleware.FollowRedirects and a non-lowercase Authorization header is affected. The workaround is to use all-lowercase "authorization" as the header key until upgrading to 1.18.3.

Workarounds

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.

Resources

Introduction commit: https://github.com/elixir-tesla/tesla/commit/2d937d5813d7cda5cd726f41824985fb655c920f
Patch commit: https://github.com/elixir-tesla/tesla/commit/db963dba67651b9abd1fc420a1d9679cf6efe182

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`tesla`	≥ 0.6.0&&< 1.18.3	1.18.3`mix deps.update tesla`

Affected Products

1 product · 1 configurations

Application

teslaelixir-tesla

≥ 1.4.0 && < 1.18.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tesla, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tesla to 1.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48595 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Summary `Tesla.Middleware.FollowRedirects` is meant to strip the `Authorization` header when following a cross-origin redirect, but performs the check with a case-sensitive comparison against the lowercase string `"authorization"`. Because Tesla preserves header keys exactly as supplied by the caller, any application that sets the header with its RFC 7235 canonical casing (`"Authorization"`) bypasses the filter entirely, leaking bearer tokens or other credentials to whatever origin the redirect points at. ### Details The filter list in `lib/tesla/middleware/follow_redirects.ex` is defin

O3 Security · Impact-Aware SCA

Is CVE-2026-48595 in your dependencies?

Find it across Hex, including transitive dependencies.

Scan my dependencies How O3 SCA works