---
id: CVE-2026-91043
title: >-
  Allocation of Resources Without Limits or Throttling vulnerability in
  elixir-mint mint allows a malicious HTTP/2 server to exhaust memory on the
  client host and cause a denial of service.


  Mint.HTTP2 enforces the client's max_header_list…
summary: >-
  Allocation of Resources Without Limits or Throttling vulnerability in
  elixir-mint mint allows a malicious HTTP/2 server to exhaust memory on the
  client host and cause a denial of service.


  Mint.HTTP2 enforces the client's max_header_list…
severity: high
cvss: 8.2
cvssVector: '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'
cwe:
  - CWE-770
vendor: elixir-mint
product: mint
affected:
  - mint >= 1.1.0 < 1.11.0
  - >-
    elixir-mint/mint >= 8e0e04680476f90f9f68db4dfeabcbe66dabfc4d <
    c7895cb022196c77ec35570c8e873a84393ff4b8
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T12:17:41.693'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91043'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-91043.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/commit/8e0e04680476f90f9f68db4dfeabcbe66dabfc4d
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/commit/c7895cb022196c77ec35570c8e873a84393ff4b8
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/security/advisories/GHSA-9x8p-qrf4-jq7g
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-91043'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-28T13:09:42.226Z'
---

## Overview

Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint allows a malicious HTTP/2 server to exhaust memory on the client host and cause a denial of service.

Mint.HTTP2 enforces the client's max_header_list_size setting only on the compressed size of an inbound header block, while RFC 9113 section 6.5.2 defines the limit on the decoded header list. An HPACK indexed field costs one byte on the wire and decodes to a dynamic table entry of up to 4 KB, and join_cookie_headers/1 in lib/mint/http2.ex copies every cookie value of a response into one new binary. A header block under the default 256 KB wire limit therefore makes the client allocate about 1 GB for a single response, and several such responses in one delivery exhaust the memory of the process that owns the connection or of the whole VM.

This issue affects mint: from 1.1.0 before 1.11.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.