# CVE-2026-82672: Elixir Mint HTTP request smuggling in chunked transfer encoding

Source: https://junglewise.ai/threats/cve-2026-82672-inconsistent-interpretation-of-http-requests-http-request  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-19. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-82672 · Severity: info · Published 2026-09-19

Mint is an HTTP client library for Elixir applications. A malicious HTTP server can exploit inconsistent parsing of chunked responses to desynchronize with intermediaries (proxies, gateways), causing the Mint client to process attacker-controlled data intended for a different request on a reused connection. This enables response poisoning and potential session hijacking in applications that reuse connections.

Technologies: [Elixir-Mint Mint](https://junglewise.ai/threats/technologies/mint). Vendors: [Elixir-Mint](https://junglewise.ai/threats/vendors/elixir-mint).

## Quick answers

**Is CVE-2026-82672 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-82672 being exploited in the wild.

**How severe is CVE-2026-82672?** Informational severity, published 19 September 2026.

**Which products and versions are affected?** Elixir-Mint Mint 0.1.0 before 1.10.1.

**Is there a fix for CVE-2026-82672?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-82672 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-82672?** Check whether you run Elixir-Mint Mint at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability lies in Mint.HTTP1.Parse.chunk_size/1 which accepts non-compliant chunk-size lines (e.g., "5ZZZZZ" or "0ZZZZ") by stopping at the first non-hex byte and ignoring the rest until CRLF, rather than validating RFC 9112 chunk extension syntax. An RFC-compliant intermediary rejects such malformed lines while Mint accepts them, causing disagreement on message boundaries. Attack requires a malicious or compromised server and connection pooling, allowing response queue poisoning on subsequent pooled requests.

## Affected products

- elixir-mint Mint 0.1.0 before 1.10.1

## Timeline

- 2026-09-19: disclosed

## References

- [https://repo.hex.pm/](https://repo.hex.pm/)
- [https://github.com/](https://github.com/)

## Related threats

- [Mint HTTP request/response smuggling in transfer encoding parsing](https://junglewise.ai/threats/cve-2026-94194-inconsistent-interpretation-of-http-requests-http-request)
- [Elixir Mint HTTP/2 frame buffer exhaustion](https://junglewise.ai/threats/cve-2026-92103-allocation-of-resources-without-limits-or-throttling)
- [Mint HTTP/2 header list memory exhaustion denial of service](https://junglewise.ai/threats/cve-2026-91043-allocation-of-resources-without-limits-or-throttling)
- [elixir-mint HTTP/1 parser algorithmic complexity denial of service](https://junglewise.ai/threats/cve-2026-82729-elixir-mint-http-1-parser-algorithmic-complexity-denial-of)
- [Elixir Mint HTTP/1 parser denial of service via unbounded buffer](https://junglewise.ai/threats/cve-2026-82728-elixir-mint-http-1-parser-denial-of-service-via-unbounded-buffer)