CVE-2026-82672 Other in mint
A malicious server can desynchronize the Mint HTTP client and intermediaries via response smuggling, poisoning subsequent requests on pooled connections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-82672?
CVE-2026-82672 is a medium-severity vulnerability in elixir-mint mint, published on 19 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-444
Which versions are affected by CVE-2026-82672?
1 open source package ship an affected version, including mint.
| Package | Affected | Fixed in |
|---|---|---|
mint Hex | From 0.1.0 | 1.10.1 |
How do I fix CVE-2026-82672?
Upgrade mint to 1.10.1 or later.
Is CVE-2026-82672 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82672 exists.
Sources
Also known as EEF-CVE-2026-82672, GHSA-rj5m-69wp-cxq9.