How severe is CVE-2026-48596?

No CVSS score has been assigned to CVE-2026-48596 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-48596?

CVE-2026-48596 affects the following packages: tesla (Hex). Ecosystems affected: Hex.

How do I fix CVE-2026-48596?

Update tesla to 1.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48596 is resolved across your whole dependency graph.

How do I detect CVE-2026-48596 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-2026-48596 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-2026-48596 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-48596 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-2026-48596?

CVE-2026-48596 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 27th 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-2026-48596?

CVE-2026-48596 is classified as CWE-113 (CWE-113). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-48596 published, and has it been updated?

CVE-2026-48596 was published on June 2, 2026 and was last updated on October 21, 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-2026-48596 — tesla

Fix: elixir-tesla/tesla@23601ed

CVE-2026-48596 is a CWE-113 vulnerability in tesla. A fix is available for tesla — see the affected versions and patch details below.

CRLF injection in Tesla.Multipart.add_content_type_param/2 allows HTTP header injection

Also known asEEF-CVE-2026-48596GHSA-q7jx-v53g-848w

Published

Jun 2, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 23, 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-2026-48596.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs27th percentile — riskier than 27% 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.Multipart.add_content_type_param/2 appends caller-supplied strings to the multipart Content-Type header with no validation. A param value containing \r\n splits the header line, allowing an attacker who controls any content-type parameter (charset, boundary parameter, etc.) to inject arbitrary headers into the outbound HTTP request.

Details

add_content_type_param/2 in lib/tesla/multipart.ex stores the supplied string directly in multipart.content_type_params without any CR/LF check. headers/1 then joins all params with "; " and appends the result verbatim to the Content-Type header value. Because HTTP headers are delimited by \r\n, a param containing that sequence breaks out of the header field and introduces new header lines before the adapter writes the request to the socket.

The precondition is that untrusted input reaches add_content_type_param/2, which is the normal pattern for applications that accept user-supplied charset values, file type parameters, or any other content-type extension fields.

PoC

Call Tesla.Multipart.add_content_type_param/2 with a value containing \r\nX-Injected: pwned.
Pass the resulting Multipart struct as the request body via any Tesla adapter.
The raw request on the wire contains X-Injected: pwned as a standalone header line.

Impact

Low severity (CVSS v4.0: 2.1). Any application using tesla 0.8.0 through 1.18.2 that passes untrusted input into Tesla.Multipart.add_content_type_param/2 is affected. Consequences range from forging arbitrary outbound request headers to potential request smuggling against the upstream server. Fixed in tesla 1.18.3.

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.

Reesources

Introduction commit: https://github.com/elixir-tesla/tesla/commit/6ebfdb9abe9c6f119408045b933d82462decd351
Patch commit: https://github.com/elixir-tesla/tesla/commit/23601edac5d22ba9407b427967b5bdbda201aec2

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`tesla`	≥ 0.8.0&&< 1.18.3	1.18.3`mix deps.update tesla`

Affected Products

1 product · 1 configurations

Application

teslaelixir-tesla

≥ 0.8.0 && < 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-2026-48596 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.Multipart.add_content_type_param/2` appends caller-supplied strings to the multipart `Content-Type` header with no validation. A param value containing `\r\n` splits the header line, allowing an attacker who controls any content-type parameter (charset, boundary parameter, etc.) to inject arbitrary headers into the outbound HTTP request. ### Details `add_content_type_param/2` in `lib/tesla/multipart.ex` stores the supplied string directly in `multipart.content_type_params` without any CR/LF check. `headers/1` then joins all params with `"; "` and appends the result verbat

O3 Security · Impact-Aware SCA

Is CVE-2026-48596 in your dependencies?

Find it across Hex, including transitive dependencies.

Scan my dependencies How O3 SCA works