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CVE.org (no NVD analysis yet)· CNA openjs

CVE-2026-109383: undici vulnerable to TLS certificate validation bypass via dropped tls options in Agent

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 6.29.1, 7.30.1, 8.12.2.

Low priority for now. Upgrade to undici undici 6.29.1, 7.30.1, 8.12.2 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 is an HTTP client library for Node.js. In versions 4.0.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its Agent dispatcher passes its constructor options through a JSON-based deep clone before forwarding them to each per-origin pool, and because JSON cannot represent functions, a caller-supplied tls option containing a checkServerIdentity callback is silently dropped before it reaches the TLS layer. As a result, a TLS peer whose certificate a custom checkServerIdentity was written to reject, but which passes Node's default hostname and chain checks, is silently accepted. Because Agent is the default dispatcher behind request, fetch, and setGlobalDispatcher, this affects the path most applications use, and EnvHttpProxyAgent is affected on its direct and no-proxy routes as well, while only applications that pass a function-valued tls option such as a custom checkServerIdentity for certificate or public-key pinning are at risk. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which preserve the tls option outside the JSON clone so custom verification callbacks are forwarded unchanged, and users should upgrade to one of those versions or later. As a workaround, pass the TLS options through connect instead of tls, or for proxied destinations use requestTls and proxyTls.

Published
Oct 15, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

36

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.

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  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nodejsundici

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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

    • 6.29.1, 7.30.1, 8.12.2not affected
    • 4.0.0 and later · before 6.29.1affected · semver
    • 7.0.0 and later · before 7.30.1affected · semver
    • 8.0.0 and later · before 8.12.2affected · semver

Affected versions

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

  • nodejs undici4.0.0 and later · before 6.29.1
  • nodejs undici7.0.0 and later · before 7.30.1
  • nodejs undici8.0.0 and later · before 8.12.2

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10nodejsbefore 1:22.23.4-1.el10_21:22.23.4-1.el10_2
AlmaLinux:10nodejs-develbefore 1:22.23.4-1.el10_21:22.23.4-1.el10_2
AlmaLinux:10nodejs-docsbefore 1:22.23.4-1.el10_21:22.23.4-1.el10_2
AlmaLinux:10nodejs-full-i18nbefore 1:22.23.4-1.el10_21:22.23.4-1.el10_2
AlmaLinux:10nodejs-libsbefore 1:22.23.4-1.el10_21:22.23.4-1.el10_2
AlmaLinux:10nodejs-npmbefore 1:10.9.9-1.22.23.4.1.el10_21:10.9.9-1.22.23.4.1.el10_2
AlmaLinux:10nodejs24before 1:24.22.1-3.el10_21:24.22.1-3.el10_2
AlmaLinux:10nodejs24-develbefore 1:24.22.1-3.el10_21:24.22.1-3.el10_2
AlmaLinux:10nodejs24-docsbefore 1:24.22.1-3.el10_21:24.22.1-3.el10_2
AlmaLinux:10nodejs24-full-i18nbefore 1:24.22.1-3.el10_21:24.22.1-3.el10_2
AlmaLinux:10nodejs24-libsbefore 1:24.22.1-3.el10_21:24.22.1-3.el10_2
AlmaLinux:10nodejs24-npmbefore 2:11.19.1-1.24.22.1.3.el10_22:11.19.1-1.24.22.1.3.el10_2
AlmaLinux:9nodejs-packagingbefore 2021.06-6.module_el9.7.0+227+123233932021.06-6.module_el9.7.0+227+12323393
AlmaLinux:9nodejs-packaging-bundlerbefore 2021.06-6.module_el9.7.0+227+123233932021.06-6.module_el9.7.0+227+12323393
Debian:12node-undicifrom 0—
Debian:14node-undicibefore 8.12.2+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-1
npmundicifrom 4.0.0 · before 6.29.16.29.1
npmundicifrom 7.0.0 · before 7.30.17.30.1
npmundicifrom 8.0.0 · before 8.12.28.12.2
Red Hat:hummingbird:1nodejs24before 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs24-binbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs24-develbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs24-docsbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs24-full-i18nbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1

+27

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-2026-84890Sep 4, 2026 · undici vulnerable to Denial of Service via unbounded decompression of compressed responses
    23Monitor
  • ← EarlierCVE-2026-109855Oct 15, 2026 · undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
    30Monitor
  • Later →CVE-2026-109841Oct 15, 2026 · undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens
    30Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
undici undici6.29.1Vendor (CNA)
undici undici7.30.1Vendor (CNA)
undici undici8.12.2Vendor (CNA)
almalinux:nodejs1:22.23.4-1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-devel1:22.23.4-1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-docs1:22.23.4-1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-full-i18n1:22.23.4-1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-libs1:22.23.4-1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-npm1:10.9.9-1.22.23.4.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs241:24.22.1-3.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-devel1:24.22.1-3.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-docs1:24.22.1-3.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-full-i18n1:24.22.1-3.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-libs1:24.22.1-3.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-npm2:11.19.1-1.24.22.1.3.el10_2 · AlmaLinux:10Package registry (OSV)
debian:node-undici8.12.2+dfsg+~cs3.2.3-1 · Debian:14Package registry (OSV)
npm:undici6.29.1Package registry (OSV)
npm:undici7.30.1Package registry (OSV)
npm:undici8.12.2Package registry (OSV)
red hat:nodejs240:24.21.0-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-bin0:24.21.0-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-devel0:24.21.0-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs260:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-bin0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-devel0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-docs0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-full-i18n0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-libs0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm0:11.20.0-1.26.11.1.0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm-bin0:26.11.1-0.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)

+5

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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 14, 2026+29 d
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.

Variant candidates

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

  • CVE-2026-8496141 days apartundici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool
    36Monitor
  • CVE-2026-9697120 days apartundici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent
    29Monitor

Bug bounty scope

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

Fixed

kotlin
val client = OkHttpClient.Builder()  .certificatePinner(    CertificatePinner.Builder()      .add("api.sirius.example", "sha256/…")      .build()  ).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.

ATT&CK techniques

—

Change log

  1. CVSS7.4 → 9.1
  2. Severityhigh → critical
  3. SSVC exploitation— → none
  4. Exploit maturity— → none
  5. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records