Vulnerability · Published Jun 2, 2026 · Assigned by EEF
CVE-2026-49754HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation
High 8.2
In plain English
A high-severity resource allocation without limits in mint from elixir-mint. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Official description
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client (HTTP/2 CONTINUATION flood). When Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, the unparsed header-block fragment is parked in conn.headers_being_processed, and every subsequent CONTINUATION frame on that stream is appended to the accumulator. Nothing in the receive path caps the accumulator: there is no per-stream size limit, no CONTINUATION frame-count limit, and max_header_list_size is only enforced on outgoing requests, never on inbound header blocks (its default is :infinity). A malicious or compromised HTTP/2 server can stream an endless sequence of CONTINUATION frames (each up to the peer-advertised SETTINGS_MAX_FRAME_SIZE) and drive the client's iolist to arbitrary size, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient. This issue affects mint: from 0.1.0 before 1.9.0.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| elixir-mint | mint | 0.1.0 – before 1.9.0 |
| elixir-mint | mint | 596ca4304504be68939c4929e0831557097962b8 – before b662d127d3028b5426c88d4c9cc7fe430491a10b |
Weakness: CWE-770 · 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