UBUNTU-CVE-2026-84961

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Source

https://ubuntu.com/security/CVE-2026-84961

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84961.json

JSON Data

https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-84961

Upstream

CVE-2026-84961

Published

2026-09-04T17:17:00Z

Modified

2026-09-16T14:01:07Z

Severity

7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

undici's BalancedPool constructor passes its entire options object through an internal deep-clone that serializes and reparses the value as JSON. Because JSON cannot represent functions, any function-valued TLS option, such as a caller-supplied checkServerIdentity callback or a custom connector inside the connect option, is silently discarded before it reaches the TLS layer. As a result a peer whose certificate the application's custom checkServerIdentity was written to reject, but which still passes Node's default hostname and chain checks, is accepted when reached through BalancedPool. The Client, Pool, and Agent dispatchers are not affected because they extract the connect and tls options before cloning. This affects undici versions from 7.24.1 up to 7.29.1 and from 8.0.0 up to 8.10.2, and only when the application supplies a function-valued connect or tls option to BalancedPool. Users should upgrade to undici 7.29.1 or 8.10.2.

References

Affected packages

Ubuntu:24.04:LTS / node-undici

Package

Name: node-undici
Purl: pkg:deb/ubuntu/node-undici?arch=source&distro=noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1

5.26.3+dfsg1+~cs23.10.12-2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "node-llhttp",
            "binary_version": "9.1.3~5.26.3+dfsg1+~cs23.10.12-2"
        },
        {
            "binary_name": "node-undici",
            "binary_version": "5.26.3+dfsg1+~cs23.10.12-2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84961.json"

Ubuntu:26.04:LTS / node-undici

Package

Name: node-undici
Purl: pkg:deb/ubuntu/node-undici?arch=source&distro=resolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

7.*

7.3.0+dfsg1+~cs24.12.11-2

7.16.0+dfsg+~cs3.2.0-2

7.18.2+dfsg+~cs3.2.0-1

7.18.2+dfsg+~cs3.2.0-1build1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "node-undici",
            "binary_version": "7.18.2+dfsg+~cs3.2.0-1build1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84961.json"