Client process stall via quadratic chunk-size parsing
Published Sep 4, 2026 · Updated Sep 4, 2026
Inefficient algorithmic complexity in Mint.HTTP1.Parse in Elixir Mint 1.9.3 allows remote attackers to stall clients via chunked responses. parse_hex_prefix/2 folds an unbounded run of hexadecimal chunk-size digits into an arbitrary-precision integer, while handle_data/2 repeatedly reparses the growing buffer. Exploitation requires a client request to an attacker-controlled or attacker-influenced URL, and CPU exhaustion stalls or crashes the calling process.
Summary
What happened
Inefficient algorithmic complexity in Mint.HTTP1.Parse in Elixir Mint 1.9.3 allows remote attackers to stall clients via chunked responses. parse_hex_prefix/2 folds an unbounded run of hexadecimal chunk-size digits into an arbitrary-precision integer, while handle_data/2 repeatedly reparses the growing buffer. Exploitation requires a client request to an attacker-controlled or attacker-influenced URL, and CPU exhaustion stalls or crashes the calling process.
The record
- CVE
- CVE-2026-82729
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- Elixir Mint
- Product
- Mint
- Classifications
- CWE-407, CAPEC-130, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.9.3 <1.10.0
- Affected versionversion=fc7d16538db7e40b56ed489f08683225cb0197fa <bd2a4e7513594997c140cfef9fe0e968712fb588
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-7p8w-j234-7qc8 proof-of-concept procedureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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