---
id: CVE-2026-82672
title: >-
  Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response
  Smuggling') vulnerability in elixir-mint mint allows a malicious HTTP/1 server
  to desynchronize a strict intermediary and the Mint client on a pooled
  connection, enabli…
summary: >-
  Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response
  Smuggling') vulnerability in elixir-mint mint allows a malicious HTTP/1 server
  to desynchronize a strict intermediary and the Mint client on a pooled
  connection, enabli…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-444
vendor: elixir-mint
product: mint
affected:
  - mint >= 0.1.0 < 1.10.1
  - >-
    elixir-mint/mint >= 60089586ec7adc9fddb09f69a2f5919ba9ac7f33 <
    c82377838dc6e275ef40bafa664fbcdf50270c60
published: '2026-09-19'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T19:09:32.273'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82672'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-82672.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/commit/60089586ec7adc9fddb09f69a2f5919ba9ac7f33
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/commit/c82377838dc6e275ef40bafa664fbcdf50270c60
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/security/advisories/GHSA-rj5m-69wp-cxq9
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-82672'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/elixir-mint/mint/security/advisories/GHSA-rj5m-69wp-cxq9
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00524
epssPercentile: 0.41999
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-21T18:29:40.588404Z'
cvssSource: cna
ingestedAt: '2026-09-19T18:08:32.248Z'
---

## Overview

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on a pooled connection, enabling response-queue poisoning against subsequent requests that share the connection.

Mint.HTTP1.Parse.chunk_size/1 in lib/mint/http1/parse.ex stops at the first non-hexadecimal byte of a chunked response's chunk-size line and returns the remainder unexamined. Mint.HTTP1.decode_body/5 in lib/mint/http1.ex then discards every byte up to the CRLF with Parse.ignore_until_crlf/1, so the accepted grammar is a run of hex digits followed by arbitrary bytes, where RFC 9112 permits only a ;-introduced chunk extension. Lines such as 5ZZZZZ and 5 9 are accepted as chunk size 5, and 0ZZZZ is accepted as the terminating chunk that ends the message body. An RFC-strict intermediary rejects such a line while Mint accepts it, so the two disagree on chunk boundaries and on where the response ends.

This issue affects mint: from 0.1.0 before 1.10.1.

## Remediation

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