EEF-CVE-2026-49753

Source
https://cna.erlef.org/osv/EEF-CVE-2026-49753.html
Import Source
https://cna.erlef.org/osv/EEF-CVE-2026-49753.json
JSON Data
https://api.osv.dev/v1/vulns/EEF-CVE-2026-49753
Aliases
  • CVE-2026-49753
  • GHSA-mjqx-c6f6-7rc2
Published
2026-06-02T14:15:17.078Z
Modified
2026-06-02T19:14:42.817Z
Severity
  • 6.3 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
HTTP response smuggling in Mint HTTP/1 client via lenient Content-Length parsing
Details

Summary

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.contentlengthheader/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.

Database specific
{
    "cpe_ids": [
        "cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"
    ],
    "cwe_ids": [
        "CWE-444"
    ],
    "capec_ids": [
        "CAPEC-273"
    ]
}
References
Credits
    • Peter Ullrich - FINDER
    • Eric Meadows-Jönsson - REMEDIATION_DEVELOPER
    • Jonatan Männchen / EEF - ANALYST

Affected packages

Hex / mint

Package

Name
mint
Purl
pkg:hex/mint

Affected ranges

Type
SEMVER
Events
Introduced
0.1.0
Fixed
1.9.0

Affected versions

0.*
0.1.0
0.2.0
0.2.1
0.3.0
0.4.0
0.5.0
1.*
1.0.0
1.1.0
1.2.0
1.2.1
1.3.0
1.4.0
1.4.1
1.4.2
1.5.0
1.5.1
1.5.2
1.6.0
1.6.1
1.6.2
1.7.0
1.7.1
1.8.0

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-49753.json"

Git / github.com/elixir-mint/mint.git

Affected ranges

Type
GIT
Repo
https://github.com/elixir-mint/mint.git
Events

Affected versions

v0.*
v0.1.0
v0.2.0
v0.2.1
v0.4.0
v0.5.0
v1.*
v1.0.0
v1.1.0
v1.2.0
v1.2.1
v1.3.0
v1.4.0
v1.4.1
v1.4.2
v1.5.0
v1.5.1
v1.5.2
v1.6.0
v1.6.1
v1.6.2
v1.7.0
v1.7.1
v1.8.0

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-49753.json"