CVE Catalog

CVE-2026-8466

High
Published: Translated: NVD NIST

Summary

CVE-2026-8466 in ninenines cowboy has a resource allocation without limits vulnerability, which can lead to denial of service through unbounded buffer accumulation during multipart header parsing.

Risk Assessment

An unauthenticated attacker can send a multipart/form-data request that forces the server to accumulate memory, potentially exhausting server resources and causing it to crash.

Recommendation

It is recommended to implement limits on buffer sizes and introduce throttling mechanisms to prevent uncontrolled memory accumulation.

Related vulnerabilities

Original NVD description (English source)

Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows denial of service via unbounded buffer accumulation in multipart header parsing. cowboy_req:read_part/3 in src/cowboy_req.erl accumulates incoming request bytes into a Buffer binary with no upper-bound check. When cow_multipart:parse_headers/2 returns more or {more, Buffer2}, the function reads up to Length bytes (default 64 KB) from the request body and recurses with the enlarged buffer. There is no equivalent of the byte_size(Acc) > Length guard present in the sibling function read_part_body/4. An unauthenticated attacker can send a multipart/form-data request whose body never yields a complete header section — for example, a body that never contains the advertised boundary delimiter, or one whose header lines never contain \r\n\r\n — and force the server process to accumulate memory linearly with the bytes the protocol layer is willing to deliver. A handful of concurrent such uploads is su

Vulnerability data from NVD (NIST) · CISA KEV · EPSS