DEBIAN-CVE-2026-84961

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Source
https://security-tracker.debian.org/tracker/CVE-2026-84961
Import Source
https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84961.json
JSON Data
https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2026-84961
Upstream
Published
2026-09-04T17:17:02Z
Modified
2026-09-16T09:00:19Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
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

Debian:12 / node-undici

Package

Name
node-undici
Purl
pkg:deb/debian/node-undici?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

5.*
5.15.0+dfsg1+~cs20.10.9.3-1
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u1
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u2
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4
5.19.1+dfsg1+~cs20.10.9.5-1
5.19.1+dfsg1+~cs20.10.9.5-2
5.22.1+dfsg1+~cs20.10.10.2-1
5.26.3+dfsg1+~cs23.10.12-1
5.26.3+dfsg1+~cs23.10.12-2
5.26.3+dfsg1+~cs23.10.12-3
5.28.0+dfsg1+~cs23.11.12.3-1
5.28.0+dfsg1+~cs23.11.12.3-2
5.28.2+dfsg1+~cs23.11.12.3-1
5.28.2+dfsg1+~cs23.11.12.3-2
5.28.2+dfsg1+~cs23.11.12.3-3
5.28.2+dfsg1+~cs23.11.12.3-4
5.28.2+dfsg1+~cs23.11.12.3-5
5.28.2+dfsg1+~cs23.11.12.3-6
5.28.4+dfsg1+~cs23.12.11-1
5.28.4+dfsg1+~cs23.12.11-2
7.*
7.1.0+dfsg1+~cs24.12.10-1
7.2.3+dfsg1+~cs24.12.11-1
7.2.3+dfsg1+~cs24.12.11-2
7.3.0+dfsg1+~cs24.12.11-1
7.3.0+dfsg1+~cs24.12.11-2
7.15.0+dfsg+~cs3.2.0-1
7.15.0+dfsg+~cs3.2.0-3
7.16.0+dfsg+~cs3.2.0-1
7.16.0+dfsg+~cs3.2.0-2
7.18.2+dfsg+~cs3.2.0-1
7.24.5+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-2
7.24.6+dfsg+~cs3.2.0-3
8.*
8.5.0+dfsg+~cs3.2.0-1
8.5.0+dfsg+~cs3.2.0-2
8.5.0+dfsg+~cs3.2.0-3
8.9.0+dfsg+~cs3.2.0-1
8.10.2+dfsg+~cs3.2.2-1

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84961.json"

Debian:13 / node-undici

Package

Name
node-undici
Purl
pkg:deb/debian/node-undici?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

7.*
7.3.0+dfsg1+~cs24.12.11-1
7.3.0+dfsg1+~cs24.12.11-2
7.15.0+dfsg+~cs3.2.0-1
7.15.0+dfsg+~cs3.2.0-3
7.16.0+dfsg+~cs3.2.0-1
7.16.0+dfsg+~cs3.2.0-2
7.18.2+dfsg+~cs3.2.0-1
7.24.5+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-2
7.24.6+dfsg+~cs3.2.0-3
8.*
8.5.0+dfsg+~cs3.2.0-1
8.5.0+dfsg+~cs3.2.0-2
8.5.0+dfsg+~cs3.2.0-3
8.9.0+dfsg+~cs3.2.0-1
8.10.2+dfsg+~cs3.2.2-1

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84961.json"

Debian:14 / node-undici

Package

Name
node-undici
Purl
pkg:deb/debian/node-undici?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
8.10.2+dfsg+~cs3.2.2-1

Affected versions

7.*
7.3.0+dfsg1+~cs24.12.11-1
7.3.0+dfsg1+~cs24.12.11-2
7.15.0+dfsg+~cs3.2.0-1
7.15.0+dfsg+~cs3.2.0-3
7.16.0+dfsg+~cs3.2.0-1
7.16.0+dfsg+~cs3.2.0-2
7.18.2+dfsg+~cs3.2.0-1
7.24.5+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-1
7.24.6+dfsg+~cs3.2.0-2
7.24.6+dfsg+~cs3.2.0-3
8.*
8.5.0+dfsg+~cs3.2.0-1
8.5.0+dfsg+~cs3.2.0-2
8.5.0+dfsg+~cs3.2.0-3
8.9.0+dfsg+~cs3.2.0-1

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84961.json"