CVE-2026-48862: Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint cli

Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint cli

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 via PUSH_PROMISE flooding. In lib/mint/http2.ex, Mint.HTTP2.decode_push_promise_headers_and_add_response/5 inserts a :reserved_remote entry into conn.streams for every promised stream ID. The neighbouring Mint.HTTP2.assert_valid_promised_stream_id/2 only verifies that the promised ID is even and not already present; client_settings.max_concurrent_streams is not consulted at promise time. The concurrency cap is only checked when the response HEADERS for the promised stream arrive, so a server that emits PUSH_PROMISE frames and withholds the matching HEADERS never trips that check. HTTP/2 server push is accepted by default (client_settings.enable_push defaults to true). A single long-lived HTTP/2 connection to a hostile server lets that server pin one conn.streams entry per PUSH_PROMISE frame it sends, with no upper bound, until the client process runs out of memory. This issue affects mint: from 0.2.0 before 1.9.0.

Description from the National Vulnerability Database, published by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

What it means for a small business

If your business uses mint, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.38%, higher than 32% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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