CVE-2026-58229 PUBLISHED

Unbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoS

Assigner: EEF
Reserved: 29.06.2026 Published: 14.07.2026 Updated: 14.07.2026

Allocation of resources without limits vulnerability in elixir-mint mint allows a remote HTTP server to exhaust memory on the client host and cause a denial of service.

The Mint.HTTP1.decode_headers/5 and Mint.HTTP1.decode_trailer_headers/4 functions in lib/mint/http1.ex accumulate every parsed response header and chunked-trailer field into a per-request list that persists across incoming TCP segments as request.headers_buffer, and only clear it when the terminating blank line is received. The section has no cap on the number of headers or on total bytes, and the underlying :erlang.decode_packet(:httph_bin, binary, []) parser is invoked with an empty option list so its per-line and per-packet size limits also default to unlimited.

A malicious HTTP server (reachable directly, via an attacker-controlled redirect, via SSRF, or via a man-in-the-middle) can stream complete header lines (or, after a chunked body, complete trailer lines) indefinitely without ever emitting the terminating blank line. The connection state grows without bound until the BEAM node is killed by the operating system's out-of-memory handler, taking down the entire application that uses Mint as an HTTP client.

This issue affects mint: from 0.1.0 before 1.9.2.

Metrics

CVSS 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
CVSS Score: 8.2

Product Status

Vendor elixir-mint
Product mint
Versions Default: unaffected
  • affected from 0.1.0 to 1.9.2 (excl.)
Vendor elixir-mint
Product mint
Versions Default: unaffected
  • affected from 3e6de4bac4821b0eb4d6109e8b1f3fb6458792c8 to 566d702e6f29105f77522ca7aabb9f64f2f4e333 (excl.)

Credits

  • zx (Jace) finder
  • Andrea Leopardi remediation developer
  • Eric Meadows-Jönsson remediation reviewer
  • Jonatan Männchen / EEF analyst

References

Problem Types

  • CWE-770 Allocation of Resources Without Limits or Throttling CWE

Impacts

  • CAPEC-130 Excessive Allocation