CVE-2026-48594 Decompression bomb in Tesla.Middleware.DecompressResponse and Tesla.Middleware.Compression
An attacker can cause a denial of service by sending a decompression bomb in an HTTP response, exhausting memory in applications using the Tesla library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48594?
CVE-2026-48594 is a high-severity denial of service vulnerability in elixir-tesla tesla, published on 2 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-tesla tesla allows a denial of service via decompression bomb in HTTP response bodies.
When Tesla.Middleware.DecompressResponse or Tesla.Middleware.Compression is included in a Tesla middleware pipeline, HTTP response bodies are decompressed eagerly with no size limit. The decompress_body/2 function in lib/tesla/middleware/compression.ex passes the entire response body to :zlib.gunzip/1 or :zlib.unzip/1 without any cap on the output size. Additionally, compression_algorithms/1 splits the content-encoding header on commas and decompress_body/2 recurses once per token, applying a decompression pass on each iteration. A server advertising content-encoding: gzip, gzip, gzip, gzip causes four recursive decompression passes, yielding exponential amplification: each gzip layer can expand its input roughly 1000x, so a payload of a few hundred bytes on the wire inflates to gigabytes of BEAM heap, exhausting memory and crashing or freezing the calling process.
This issue affects tesla: from 0.6.0 before 1.18.3.
Weakness: CWE-409
Which versions are affected by CVE-2026-48594?
3 open source packages ship an affected version, including tesla. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tesla Hex | From 0.6.0 | 1.18.3 |
tesla Hex | From 0.6.0 | 1.18.3 |
tesla Hex | From 0.6.0 | 1.18.3 |
Products include Elixir-Tesla Tesla.
How do I fix CVE-2026-48594?
Upgrade tesla to 1.18.3 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-48594 being exploited?
There is no known exploitation of CVE-2026-48594 in the wild and no public exploit code.
Other vulnerabilities in elixir-tesla tesla
- CVE-2026-48595 Authorization header leaks to third-party origin on cross-origin redirect in Tesla.Middleware.FollowRedirects
- CVE-2026-48597 Atom table exhaustion via untrusted URL scheme in Tesla.Adapter.Mint
- CVE-2026-48596 CRLF injection in Tesla.Multipart.add_content_type_param/2 allows HTTP header injection
- CVE-2026-48598 CRLF injection in Tesla.Multipart disposition parameters allows multipart part header injection
Sources
Also known as EEF-CVE-2026-48594, GHSA-mc85-72gr-vm9f.