CVE-2026-82672
Unvalidated chunk-size line tail in Mint HTTP/1 client enables response smuggling against strict intermediaries on pooled connections
Description
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.
INFO
Published Date :
Sept. 19, 2026, 5:16 p.m.
Last Modified :
Sept. 19, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | ||||
| CVSS 4.0 | MEDIUM | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db |
Solution
- Update elixir-mint mint to version 1.10.1 or later.
- Apply security patches promptly.
- Validate HTTP request parsing logic.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-82672.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-82672 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-82672
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-82672 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-82672 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Sep. 19, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-444 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82672.json">CVE-2026-82672</a> Added Reference https://cna.erlef.org/cves/CVE-2026-82672.html Added Reference https://github.com/elixir-mint/mint/commit/60089586ec7adc9fddb09f69a2f5919ba9ac7f33 Added Reference https://github.com/elixir-mint/mint/commit/c82377838dc6e275ef40bafa664fbcdf50270c60 Added Reference https://github.com/elixir-mint/mint/security/advisories/GHSA-rj5m-69wp-cxq9 Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-82672