CVE-2026-59249
- Source
- https://cve.org/CVERecord?id=CVE-2026-59249
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59249.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-59249
- Aliases
-
- EEF-CVE-2026-59249
- GHSA-x3x7-96vm-6h2w
- Published
- 2026-07-16T11:39:29.939Z
- Modified
- 2026-08-07T11:46:41.677465121Z
- Severity
-
- 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Sign-tolerant HTTP/1 chunk-size parser in Mint enables response smuggling against strict intermediaries on pooled connections
- Details
-
Inconsistent interpretation of HTTP requests (HTTP response smuggling) vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on the same pooled connection, enabling response-queue poisoning against subsequent requests that share the connection.
The Mint.HTTP1.decode_body/5 function in lib/mint/http1.ex parses the chunk-size line of a Transfer-Encoding: chunked response with Integer.parse(data, 16). RFC 7230 defines chunk-size = 1*HEXDIG and forbids any sign prefix, but Integer.parse/2 accepts an optional leading + or -. A chunk-size line of +5 is accepted as a five-byte chunk; lines of +0 and -0 are accepted as the terminating zero-length chunk and end the message body early.
An RFC-strict intermediary in the response path rejects these forms, so the intermediary and the Mint client disagree on where one response ends and the next begins. On a pooled keep-alive connection, an attacker-influenced origin can inject bytes that the client attributes to the next legitimate response on the same connection, poisoning the response queue and corrupting the responses returned to unrelated in-flight requests.
This issue affects mint: from 0.1.0 before 1.9.3.
- Database specific
{ "cna_assigner": "EEF", "cwe_ids": [ "CWE-444" ], "unresolved_ranges": [ { "extracted_events": [ { "introduced": "60089586ec7adc9fddb09f69a2f5919ba9ac7f33" }, { "fixed": "fc7d16538db7e40b56ed489f08683225cb0197fa" } ], "source": "AFFECTED_FIELD" } ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59249.json" }- References
-
- https://cna.erlef.org/cves/CVE-2026-59249.html
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-59249
- https://repo.hex.pm
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59249.json
- https://github.com/elixir-mint/mint/security/advisories/GHSA-x3x7-96vm-6h2w
- https://nvd.nist.gov/vuln/detail/CVE-2026-59249
- https://github.com/elixir-mint/mint/commit/fc7d16538db7e40b56ed489f08683225cb0197fa
- https://github.com/elixir-mint/mint