{"cve":"CVE-2026-49753","nvd":{"published":"2026-06-02T16:16:44.777","modified":"2026-07-22T19:10:00.120","status":"Deferred","description":"Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint Mint allows attacker-controlled HTTP/1 servers to desynchronise response framing on shared connections.\n\nMint's HTTP/1 Content-Length parser, Mint.HTTP1.Parse.content_length_header/1 in lib/mint/http1/parse.ex, parses the header value with Integer.parse/1, which accepts an optional + or - sign prefix. The length >= 0 guard rejects negatives, but inputs such as +0 or +123 are returned as valid lengths. RFC 7230 specifies Content-Length = 1*DIGIT, with no sign character permitted.\n\nA fronting proxy or load balancer that strictly enforces the grammar will reject or reframe a header like Content-Length: +0, while Mint silently treats it as zero. When Mint reuses the socket (keep-alive, pipelining, or any pooled connection shared across requesters), the parser disagreement is a response-smuggling primitive: the proxy delimits the body one way, Mint another, and bytes from one response get attributed to the next. Where the same Mint connection is shared across trust boundaries, an attacker-controlled upstream can leak bytes into a different consumer's response stream.\n\nThis issue affects mint: from 0.1.0 before 1.9.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-444"],"references":["https://cna.erlef.org/cves/CVE-2026-49753.html","https://github.com/elixir-mint/mint/commit/47e48027480228e4e32a0b4df39db497b4804921","https://github.com/elixir-mint/mint/security/advisories/GHSA-mjqx-c6f6-7rc2","https://osv.dev/vulnerability/EEF-CVE-2026-49753","https://github.com/elixir-mint/mint/security/advisories/GHSA-mjqx-c6f6-7rc2"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:37:48.043517290+00:00"},"epss":{"cve":"CVE-2026-49753","score":0.00301,"percentile":0.22895,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}