CVE-2026-49753Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint Mint allows attacker-controlled HTTP/1 servers to desynchronise response framing on share…
Updated under an hour ago ()
Does this affect you?
It lists no affected products yet. Add what you run and Signals checks it as products are added.
No exploitation reported and no EPSS estimate yet.
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. Mint'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. A 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. This issue affects mint: from 0.1.0 before 1.9.0.
- CVSS
- 6.3 MEDIUM (v4.0, NVD)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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Weakness (CWE)
- CWE-444
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Deferred
- Record last updated
- Jul 22, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
No affected products are listed yet.
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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.