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.
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Fri, 04 Sep 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Quadratic chunk-size parsing in Mint.HTTP1.Parse allows CPU-exhaustion DoS | |
| First Time appeared |
Elixir-mint
Elixir-mint mint |
|
| Weaknesses | CWE-407 | |
| CPEs | cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Elixir-mint
Elixir-mint mint |
|
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-09-04T14:31:20.562Z
Reserved: 2026-08-31T00:59:08.960Z
Link: CVE-2026-82729
No data.
Status : Received
Published: 2026-09-04T15:17:36.120
Modified: 2026-09-04T15:17:36.120
Link: CVE-2026-82729
No data.
OpenCVE Enrichment
Updated: 2026-09-04T15:30:06Z
