Vulnerability · Published Jun 2, 2026 · Assigned by EEF
CVE-2026-48594Decompression bomb in Tesla.Middleware.DecompressResponse and Tesla.Middleware.Compression
High 8.2
In plain English
A high-severity security flaw in tesla from elixir-tesla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| elixir-tesla | tesla | 0.6.0 – before 1.18.3 |
| elixir-tesla | tesla | 5bd90bb5cf0d15e375edc2a66fa322292940fce2 – before 340f75b5d191dc747ef7ac6365bd002d1cd55a9d |
Weakness: CWE-409 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N