CVE-2026-56810
HighCVSS 8.7Exploitation Probability (EPSS)
Low risk44th percentile - higher than 44% 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.
Other vulnerabilities in mint
See all- CVE-2026-92103Medium
A vulnerability in the mint library (Elixir) allows a malicious HTTP/2 server to make the client buffer up to about 16 MiB per connection in frames it should reject, consuming client memory. This occurs because the frame is compared with the maximum size only after the entire declared payload has arrived, leading to excessive memory usage.
- CVE-2026-91043High
The mint library (Elixir) has a resource allocation vulnerability allowing a malicious HTTP/2 server to exhaust client memory and cause denial of service. Affected versions are from 1.1.0 before 1.10.2.
- CVE-2026-82672Medium
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on a pooled connection, enabling response-queue poisoning against subsequent requests that share the connection. Mint.HTTP1.Parse.chunk_size/1 stops at the first non-hexadecimal byte of a chunked response's chunk-size line and returns the remainder unexamined, and Mint.HTTP1.decode_body/5 discards bytes up to the CRLF, so lines such as 5ZZZZZ and 5 9 are accepted as chunk size 5, and 0ZZZZ as the terminating chunk. This issue affects mint from 0.1.0 before 1.10.1.
- CVE-2026-82728High
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a remote HTTP server to exhaust memory on the client host and cause a denial of service. Two HTTP/1 response-parser states accumulate server data without any cap. In lib/mint/http1.ex, decode_status_line/4 stores the unconsumed data in conn.buffer when the status line is incomplete, and decode_body/5 does the same for an unterminated chunk-extension line. Both wait for a CRLF the server never has to send, and conn.buffer is prepended to every subsequent socket message. The :max_header_list_size budget is wired only into decode_headers/5 and decode_trailer_headers/4, so neither of these states is covered by it. A malicious server, or one reached through an attacker-controlled redirect or a fetched URL, streams bytes indefinitely until the BEAM node is killed by the operating system out-of-memory handler. The chunk-extension variant is reached after a valid status line and a complete, valid header section, so an intermediary inspecting only headers sees an ordinary 200 response. This issue affects mint: from 0.1.0 before 1.10.0.
- CVE-2026-59249Medium
A vulnerability in the Mint library (versions 0.1.0 through 1.9.2) allows HTTP response smuggling by accepting a plus/minus sign in the chunk-size line of Transfer-Encoding: chunked. A malicious HTTP/1 server can exploit this interpretation mismatch to poison the response queue on a shared keep-alive connection, causing subsequent requests to receive forged responses.
- CVE-2026-59246Medium
A vulnerability in the Mint library for Elixir allows a remote HTTP/2 server to exhaust client memory by sending an infinite stream of zero-length CONTINUATION frames. The header accumulation mechanism lacks proper protection against this attack, leading to denial of service (DoS).
- CVE-2026-58229High
A vulnerability in the Mint library for Elixir allows a remote HTTP server to exhaust client memory and cause a denial of service (DoS). The HTTP header decoding functions accumulate headers without limits, and the parser has no cap on the number or size of headers, enabling an attacker to stream infinite header lines without a terminating blank line.
- CVE-2026-49754High
A vulnerability in the Mint library for Elixir allows an attacker-controlled HTTP/2 server to exhaust client memory via a CONTINUATION frame flood. There is no limit on the header accumulator size, leading to memory exhaustion and BEAM process death.
- CVE-2026-49753Medium
Elixir Mint library before version 1.9.0 is vulnerable to HTTP response smuggling. The Content-Length parser accepts + and - signs, violating RFC 7230. An attacker-controlled HTTP/1 server can desynchronize response framing on shared connections.
- CVE-2026-48862High
A vulnerability in the Mint library for Elixir allows an attacker-controlled HTTP/2 server to exhaust client memory via PUSH_PROMISE flooding. The server can create an unlimited number of stream entries without checking the max_concurrent_streams limit, leading to memory exhaustion.
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

