CVE-2026-56810
HighCVSS 8.7Exploitation Probability (EPSS)
Low risk26th percentile - higher than 26% of all known CVEs
Summary
A vulnerability in the Mint library (Mint.HTTP1 module) allows a remote server to exhaust client memory by sending a chunked transfer-encoded response with a declared huge chunk size (e.g., 2 GiB) and slowly sending data without ever completing the chunk. The client buffers all received bytes without emitting them to the caller, leading to uncontrolled memory growth and out-of-memory conditions.
Risk Assessment
The organization is at risk of a DoS attack when its application using the Mint library processes data from untrusted servers (e.g., following redirects, fetching user-supplied URLs, or handling webhooks). An attacker can crash the application due to memory exhaustion.
Recommendation
Immediately upgrade the mint library to version 1.9.1 or later, which includes a fix that limits the size of buffered data.
Original NVD description (English source)
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint (Mint.HTTP1 module) allows a denial of service via an oversized chunked transfer-encoded response. This vulnerability is associated with program files lib/mint/http1.ex and program routines 'Elixir.Mint.HTTP1':decode_body/5, 'Elixir.Mint.HTTP1':add_body_to_buffer/2. When Mint decodes a chunked HTTP response body, it accumulates each partial fragment of the current chunk in the connection's data_buffer (an unbounded iolist) via add_body_to_buffer/2 and does not emit the data to the caller until the full declared chunk length has been received. The chunk size is taken directly from the server and parsed with no upper bound, so a malicious or compromised server can announce one enormous chunk (for example a size line of 7FFFFFFF, about 2 GiB) and then send the body bytes slowly without ever completing the chunk. The client buffers every received byte while it waits for a completion that never arrives, and because no data responses are produced until the chunk finishes, a caller that otherwise streams large content-length bodies safely gains no protection. An unauthenticated remote server (reachable whenever a client follows redirects, fetches user-supplied URLs, or processes webhooks) can drive the client's memory arbitrarily high and trigger an out-of-memory condition. This issue affects mint: from 0.5.0 before 1.9.1.