# CVE-2026-82729

## Summary

- **CVE ID:** CVE-2026-82729
- **Severity:** MEDIUM
- **CVSS Score:** 6.3 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N)
- **CWE:** CWE-407
- **Published:** Sep 4, 2026
- **Last Modified:** Sep 4, 2026

## Description

Inefficient Algorithmic Complexity vulnerability in elixir-mint mint allows a remote HTTP server to exhaust CPU on the client host and cause a denial of service.

parse_hex_prefix/2 in lib/mint/http1/parse.ex folds each hex digit of a chunked response's chunk-size field into an arbitrary-precision accumulator with acc * 16 + digit and imposes no limit on the digit count. Because the accumulator grows without bound, the multiplication is not constant time and one pass over N digits costs O(N squared). handle_data/2 prepends conn.buffer and re-parses from the start on every socket message, so a server that dribbles the digits out in small packets makes the client pay that cost repeatedly. A run of roughly 512,000 hex digits costs over ten seconds of CPU in a single pass, measured on stock defaults. The parser reaches this state after a valid status line and a complete, valid header section, so an intermediary inspecting only headers sees an ordinary 200 response.

This issue affects mint: from 1.9.3 before 1.10.0.

## Affected Products

- elixir-mint — mint (1.9.3)
- elixir-mint — mint (fc7d16538db7e40b56ed489f08683225cb0197fa)

## References

- [CNA](https://github.com/elixir-mint/mint/security/advisories/GHSA-7p8w-j234-7qc8)
- [CNA](https://cna.erlef.org/cves/CVE-2026-82729.html)
- [CNA](https://osv.dev/vulnerability/EEF-CVE-2026-82729)
- [CNA](https://github.com/elixir-mint/mint/commit/bd2a4e7513594997c140cfef9fe0e968712fb588)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.49%
- **EPSS Percentile:** 40.4

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._