USN-8989-1

Source
https://ubuntu.com/security/notices/USN-8989-1
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8989-1.json
JSON Data
https://api.osv.dev/v1/vulns/USN-8989-1
Upstream
CVE (13)
Related
Published
2026-11-03T17:12:03Z
Modified
2026-11-04T03:43:07Z
Summary
ruby-rack vulnerabilities
Details

Andrew Lacambra discovered that Rack did not properly parse certain regular expressions. An attacker could possibly use this issue to bypass network security filters. (CVE-2026-26961)

William T. Nelson discovered that Rack did not handle multipart headers correctly. An attacker could possibly use this issue to cause downstream parsing issues or a denial of service. (CVE-2026-26962)

It was discovered that Rack did not handle the Forwarded header correctly. An attacker could possibly use this issue to manipulate header values. (CVE-2026-32762)

It was discovered that Rack could consume excessive CPU when handling certain Accept-Encoding values. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-34230)

Haruki Oyama discovered that certain configurations of Rack could erroneously fail to derive the displayed directory path, and expose the full file system path. An attacker could possibly use this issue to disclose deployment details such as layout and usernames. (CVE-2026-34763)

It was discovered that Rack did not properly handle static file paths. An attacker could possibly use this issue to exfiltrate unintentionally served data. (CVE-2026-34785)

Haruki Oyama discovered that Rack did not apply header rules to certain requests for URL-encoded static paths. An attacker could possibly use this issue to bypass security-relevant response headers. (CVE-2026-34786)

It was discovered that Rack did not limit the number of ranges requested in the Range header. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-34826)

It was discovered that Rack could consume excessive CPU when parsing certain multipart parameters. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-34827)

It was discovered that Rack could consume unbounded disk space when handling requests without a Content-Length header. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-34829)

Mehtab Zafar discovered that Rack directly interpreted the X-Accel-Mapping header as a regular expression without escaping. An attacker could possibly use this issue to exfiltrate arbitrary files from internal locations. (CVE-2026-34830)

It was discovered that Rack did not properly handle messages with Unicode. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-34831)

It was discovered that Rack did not properly parse the Host header. An attacker could possibly use this issue to bypass security filters or poison generated links. (CVE-2026-34835)

References

Affected packages

Ubuntu:26.04:LTS / ruby-rack

Package

Name
ruby-rack
Purl
pkg:deb/ubuntu/ruby-rack?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.2.4-1ubuntu1.1

Affected versions

3.*
3.1.16-0.1
3.1.18-1
3.1.18-1build1
3.2.4-1ubuntu1

Ecosystem specific

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "ruby-rack",
            "binary_version": "3.2.4-1ubuntu1.1"
        }
    ]
}

Database specific

cves_map
{
    "cves": [
        {
            "id": "CVE-2026-26961",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-26962",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-32762",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34230",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34763",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34785",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34786",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34826",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34827",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34829",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34830",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34831",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-34835",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:26.04:LTS"
}
source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8989-1.json"