Vulnerability in tesla (CVE-2026-48595)
Summary
Vulnerability in tesla (CVE-2026-48595). Confidential information can be exposed externally. Exploitable via Tesla.Middleware.FollowRedirects. Mitigation: upgrade to 1.18.3 or later.
Original description
The description as published by the source.
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.
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.
Configurations
The application must include Tesla.Middleware.FollowRedirects in its Tesla middleware pipeline.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48595 has been found in tesla.
Attackers can target a specific entry point like Tesla.Middleware.FollowRedirects over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.9/10.
What to do: upgrade tesla to 1.18.3 or later.
If unsure, ask your IT team or search "tesla CVE-2026-48595" on the vendor's site.
CVE-2026-48595 (tesla) — CWE-178 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Tesla.Middleware.FollowRedirects / Authorization / tesla / Tesla.Middleware.Headers
Patched: 1.18.3 — apply immediately
Workaround: Normalize all header keys to lowercase before passing them to Tesla.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-178) exists in tesla. Attackers reach the vulnerable code path via Tesla.Middleware.FollowRedirects without authentication.
Check the vendor advisory for the affected versions of tesla. Attack surface: Tesla.Middleware.FollowRedirects / Authorization / tesla / Tesla.Middleware.Headers.
Severity: Medium (CVSS 5.9/10). Confidential information can be exposed externally.
Update to 1.18.3.
Workaround: Normalize all header keys to lowercase before passing them to Tesla.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'tesla' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'tesla' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
teslaを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Normalize all header keys to lowercase before passing them to Tesla.パッチが適用されるまでの応急処置として、Normalize all header keys to lowercase before passing them to Tesla. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade tesla to 1.18.3ステージング環境で 1.18.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package hex.pm
- package github.com
- patch github.com
- web cna.erlef.org
- web osv.dev
- web github.com
- web github.com