DEBIAN-CVE-2026-34835
Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Request parses the Host header using an AUTHORITY regular expression that accepts characters not permitted in RFC-compliant hostnames, including /, ?, #, and @. Because req.host returns the full parsed value, applications that validate hosts using naive prefix or suffix checks can be bypassed. This can lead to host header poisoning in applications that use req.host, req.url, or req.base_url for link generation, redirects, or origin validation. This issue has been patched in versions 3.1.21 and 3.2.6.
DEBIAN-CVE-2026-34835
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-34835
ruby-rack
Source reference: /affected/0/package/name
- Affected versions
- 3.1.16-0.1
Source reference:
/affected/0/versions3.1.18-1Source reference:
/affected/0/versions3.1.18-1~deb13u1Source reference:
/affected/0/versions3.1.20-0+deb13u1Source reference:
/affected/0/versions - Fixed versions
- 3.1.20-0+deb13u2
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
ruby-rack
Source reference: /affected/1/package/name
- Affected versions
- 3.1.16-0.1
Source reference:
/affected/1/versions3.1.18-1Source reference:
/affected/1/versions3.1.18-1~deb13u1Source reference:
/affected/1/versions3.2.4-1Source reference:
/affected/1/versions3.2.5-1Source reference:
/affected/1/versions3.2.5-2Source reference:
/affected/1/versions3.2.6-1Source reference:
/affected/1/versions - Fixed versions
- 3.2.6-2
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.20-0+deb13u2"
}
]
}
],
"package": {
"name": "ruby-rack",
"purl": "pkg:deb/debian/ruby-rack?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.1.16-0.1",
"3.1.18-1",
"3.1.18-1~deb13u1",
"3.1.20-0+deb13u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34835.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.2.6-2"
}
]
}
],
"package": {
"name": "ruby-rack",
"purl": "pkg:deb/debian/ruby-rack?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.1.16-0.1",
"3.1.18-1",
"3.1.18-1~deb13u1",
"3.2.4-1",
"3.2.5-1",
"3.2.5-2",
"3.2.6-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34835.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57541 · Revision 1
- Added to Heist Feed
- Publisher date