CVE-2026-49753
MediumCVSS 6.3Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
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.
Risk Assessment
An attacker can smuggle HTTP responses, potentially leaking data between different consumers on a shared connection.
Recommendation
Update the Mint library to version 1.9.0 or later.
Other vulnerabilities in Mint
See all- 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-2026-92103Medium
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-2026-59246Medium
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-2026-56810High
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.
- 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-2026-48862High
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)
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint Mint allows attacker-controlled HTTP/1 servers to desynchronise response framing on shared connections. Mint's HTTP/1 Content-Length parser, Mint.HTTP1.Parse.content_length_header/1 in lib/mint/http1/parse.ex, parses the header value with Integer.parse/1, which accepts an optional + or - sign prefix. The length >= 0 guard rejects negatives, but inputs such as +0 or +123 are returned as valid lengths. RFC 7230 specifies Content-Length = 1*DIGIT, with no sign character permitted. A fronting proxy or load balancer that strictly enforces the grammar will reject or reframe a header like Content-Length: +0, while Mint silently treats it as zero. When Mint reuses the socket (keep-alive, pipelining, or any pooled connection shared across requesters), the parser disagreement is a response-smuggling primitive: the proxy delimits the body one way, Mint another, and bytes from one response get attributed to the next. Where the same Mint connection is shared across trust boundaries, an attacker-controlled upstream can leak bytes into a different consumer's response stream. This issue affects mint: from 0.1.0 before 1.9.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

