NVD / CVE Program· CNA openjs

CVE-2026-84961: undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 36/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: undici undici 7.29.1, 8.10.2.

Low priority for now. Upgrade to undici undici 7.29.1, 8.10.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published: Sep 4, 2026
Updated: Sep 15, 2026
EPSS: 0.1% · 8th percentile
CWE: CWE-295

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 36 / 40 · 9.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 9.1
CNA · openjs: 7.4; 1.7 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

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Vendor	Product	CPE
nodejs	undici	cpe:2.3:a:nodejs:undici

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (openjs). Independent of NVD's CPE analysis and usually ahead of it.

undici undici
- 7.29.1, 8.10.2not affected
- 7.24.1 and later · before 7.29.1affected · semver
- 8.0.0 and later · before 8.10.2affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

nodejs undici7.24.1 and later · before 7.29.1
nodejs undici8.0.0 and later · before 8.10.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

+71

Same product

nodejs: all records

Other highest-scoring records for the same primary product.

CVE-2022-35949`undici.request` vulnerable to SSRF using absolute URL on `pathname`
40Plan
CVE-2026-1525undici is vulnerable to Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
39Monitor
CVE-2026-109829undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects
36Monitor

Published before and after this one in the same product

← EarlierCVE-2026-84933Sep 4, 2026 · undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
32Monitor
← EarlierCVE-2026-84947Sep 4, 2026 · undici vulnerable to response truncation via oversized chunked responses in the dump interceptor
21Monitor
Later →CVE-2026-85008Sep 4, 2026 · undici vulnerable to caching and replay of unsafe HTTP method responses
21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
undici undici	7.29.1	Vendor (CNA)
undici undici	8.10.2	Vendor (CNA)
almalinux:nodejs	1:24.21.0-1.module_el8.10.0+4292+21afb960 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs	1:24.21.0-1.module_el9.8.0+321+1555b6a2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs-devel	1:24.21.0-1.module_el8.10.0+4292+21afb960 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs-devel	1:24.21.0-1.module_el9.8.0+321+1555b6a2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs-docs	1:24.21.0-1.module_el8.10.0+4292+21afb960 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs-docs	1:24.21.0-1.module_el9.8.0+321+1555b6a2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs-full-i18n	1:24.21.0-1.module_el8.10.0+4292+21afb960 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs-full-i18n	1:24.21.0-1.module_el9.8.0+321+1555b6a2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs-libs	1:24.21.0-1.module_el8.10.0+4292+21afb960 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs-libs	1:24.21.0-1.module_el9.8.0+321+1555b6a2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs-nodemon	3.1.14-2.module_el8.10.0+4250+09238ed4 · AlmaLinux:8	Package registry (OSV)
almalinux:nodejs-nodemon	3.1.14-3.module_el9.8.0+292+f4eaf8b2 · AlmaLinux:9	Package registry (OSV)
almalinux:nodejs24	1:24.21.0-1.el10_2 · AlmaLinux:10	Package registry (OSV)
almalinux:nodejs24-devel	1:24.21.0-1.el10_2 · AlmaLinux:10	Package registry (OSV)
almalinux:nodejs24-docs	1:24.21.0-1.el10_2 · AlmaLinux:10	Package registry (OSV)
almalinux:nodejs24-full-i18n	1:24.21.0-1.el10_2 · AlmaLinux:10	Package registry (OSV)
almalinux:nodejs24-libs	1:24.21.0-1.el10_2 · AlmaLinux:10	Package registry (OSV)
almalinux:nodejs24-npm	2:11.19.0-1.24.21.0.1.el10_2 · AlmaLinux:10	Package registry (OSV)
debian:node-undici	8.10.2+dfsg+~cs3.2.2-1 · Debian:14	Package registry (OSV)
npm:undici	7.29.1	Package registry (OSV)
npm:undici	8.10.2	Package registry (OSV)
opensuse:pi-coding-agent	0.87.1-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:grafana12.4	0:12.4.10-0.2.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:nodejs24	0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:nodejs24-bin	0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:nodejs24-debuginfo	1:24.21.0-1.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:nodejs24-devel	0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:nodejs24-docs	0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1	Package registry (OSV)

+10

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

MegaManSecreporter
mcollinaremediation developer
UlisesGasconremediation reviewer

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-10938341 days apartundici vulnerable to TLS certificate validation bypass via dropped tls options in Agent
36Monitor
CVE-2026-969779 days apartundici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent
29Monitor

Bug bounty scope

Node.jsHackerOne · paid

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: patch commit or PR link.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

cna.openjsf.org/security-advisories.html

Show all references (1 more)

github.com/nodejs/undici/security/advisories/GHSA-w293-vg96-wgc3

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Ecosystem	Package	Affected range	Fix
AlmaLinux:10	nodejs24	before 1:24.21.0-1.el10_2	1:24.21.0-1.el10_2
AlmaLinux:10	nodejs24-devel	before 1:24.21.0-1.el10_2	1:24.21.0-1.el10_2
AlmaLinux:10	nodejs24-docs	before 1:24.21.0-1.el10_2	1:24.21.0-1.el10_2
AlmaLinux:10	nodejs24-full-i18n	before 1:24.21.0-1.el10_2	1:24.21.0-1.el10_2
AlmaLinux:10	nodejs24-libs	before 1:24.21.0-1.el10_2	1:24.21.0-1.el10_2
AlmaLinux:10	nodejs24-npm	before 2:11.19.0-1.24.21.0.1.el10_2	2:11.19.0-1.24.21.0.1.el10_2
AlmaLinux:8	nodejs	before 1:24.21.0-1.module_el8.10.0+4292+21afb960	1:24.21.0-1.module_el8.10.0+4292+21afb960
AlmaLinux:8	nodejs-devel	before 1:24.21.0-1.module_el8.10.0+4292+21afb960	1:24.21.0-1.module_el8.10.0+4292+21afb960
AlmaLinux:8	nodejs-docs	before 1:24.21.0-1.module_el8.10.0+4292+21afb960	1:24.21.0-1.module_el8.10.0+4292+21afb960
AlmaLinux:8	nodejs-full-i18n	before 1:24.21.0-1.module_el8.10.0+4292+21afb960	1:24.21.0-1.module_el8.10.0+4292+21afb960
AlmaLinux:8	nodejs-libs	before 1:24.21.0-1.module_el8.10.0+4292+21afb960	1:24.21.0-1.module_el8.10.0+4292+21afb960
AlmaLinux:8	nodejs-nodemon	before 3.1.14-2.module_el8.10.0+4250+09238ed4	3.1.14-2.module_el8.10.0+4250+09238ed4
AlmaLinux:8	nodejs-packaging	before 2021.06-6.module_el8.10.0+4086+70facd4a	2021.06-6.module_el8.10.0+4086+70facd4a
AlmaLinux:8	nodejs-packaging-bundler	before 2021.06-6.module_el8.10.0+4086+70facd4a	2021.06-6.module_el8.10.0+4086+70facd4a
AlmaLinux:8	npm	before 1:11.19.0-1.24.21.0.1.module_el8.10.0+4292+21afb960	1:11.19.0-1.24.21.0.1.module_el8.10.0+4292+21afb960
AlmaLinux:8	v8-13.6-devel	before 3:13.6.233.17-1.24.21.0.1.module_el8.10.0+4292+21afb960	3:13.6.233.17-1.24.21.0.1.module_el8.10.0+4292+21afb960
AlmaLinux:9	nodejs	before 1:24.21.0-1.module_el9.8.0+321+1555b6a2	1:24.21.0-1.module_el9.8.0+321+1555b6a2
AlmaLinux:9	nodejs-devel	before 1:24.21.0-1.module_el9.8.0+321+1555b6a2	1:24.21.0-1.module_el9.8.0+321+1555b6a2
AlmaLinux:9	nodejs-docs	before 1:24.21.0-1.module_el9.8.0+321+1555b6a2	1:24.21.0-1.module_el9.8.0+321+1555b6a2
AlmaLinux:9	nodejs-full-i18n	before 1:24.21.0-1.module_el9.8.0+321+1555b6a2	1:24.21.0-1.module_el9.8.0+321+1555b6a2
AlmaLinux:9	nodejs-libs	before 1:24.21.0-1.module_el9.8.0+321+1555b6a2	1:24.21.0-1.module_el9.8.0+321+1555b6a2
AlmaLinux:9	nodejs-nodemon	before 3.1.14-3.module_el9.8.0+292+f4eaf8b2	3.1.14-3.module_el9.8.0+292+f4eaf8b2
AlmaLinux:9	nodejs-packaging	before 2021.06-6.module_el9.7.0+209+ecf6523e	2021.06-6.module_el9.7.0+209+ecf6523e
AlmaLinux:9	nodejs-packaging-bundler	before 2021.06-6.module_el9.7.0+209+ecf6523e	2021.06-6.module_el9.7.0+209+ecf6523e