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Noroxi
NVD / CVE Program· CNA openjs

CVE-2026-16729: undici vulnerable to cookie attribute injection via unsanitized domain and unparsed setCookie fields

Noroxi assessment

Priority: Monitor (action score 26/100)

  • 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: 0.27% (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 6.28.0, 7.29.0, 8.9.0; azl3 nodejs 24.21.0-1 on Azure Linux 3.0 24.22.0-1.

Low priority for now. Upgrade to undici undici 6.28.0, 7.29.0, 8.9.0; azl3 nodejs 24.21.0-1 on Azure Linux 3.0 24.22.0-1 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 setCookie function does not fully sanitize cookie attributes. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a domain value is not checked for semicolons and entries in the unparsed array are not sanitized, so attacker-influenced input can inject additional cookie attributes. For example, a domain value containing a semicolon can append attributes such as SameSite, and an unparsed entry can inject attributes such as HttpOnly, without the caller setting them. Applications that pass user-controlled input to these fields, such as multi-tenant or reverse-proxy servers that scope session cookies to a tenant-supplied domain, can have SameSite CSRF protections bypassed, or the Secure, HttpOnly, and SameSite attributes forced, stripped, or overridden. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Jul 29, 2026
Updated
Aug 5, 2026
EPSS
0.2% · 20th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.5
CNA · openjs
4.8
1.7 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/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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  • 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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Follow CVE-2026-16729

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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?

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

Affected versions

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

  • nodejs undicibefore 6.28.0
  • nodejs undici7.0.0 and later · before 7.29.0
  • nodejs undici8.0.0 and later · before 8.9.0

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

    • 6.28.0, 7.29.0, 8.9.0not affected
    • before 6.28.0affected · semver
    • 7.0.0 and later · before 7.29.0affected · semver
    • 8.0.0 and later · before 8.9.0affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12node-undicifrom 0—
Debian:14node-undicibefore 8.9.0+dfsg+~cs3.2.0-18.9.0+dfsg+~cs3.2.0-1
npmundicifrom 7.0.0 · before 7.29.07.29.0
npmundicifrom 8.0.0 · before 8.9.08.9.0
npmundicibefore 6.28.06.28.0
Red Hat:hummingbird:1nodejs24before 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-binbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-develbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-docsbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-full-i18nbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-libsbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs24-npmbefore 0:11.16.0-1.24.18.1.0.1.hum10:11.16.0-1.24.18.1.0.1.hum1
Red Hat:hummingbird:1nodejs24-npm-binbefore 0:24.18.1-0.1.hum10:24.18.1-0.1.hum1
Red Hat:hummingbird:1nodejs26before 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-binbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-develbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-docsbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-full-i18nbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-libsbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
Red Hat:hummingbird:1nodejs26-npmbefore 0:11.17.0-1.26.5.1.1.5.hum10:11.17.0-1.26.5.1.1.5.hum1
Red Hat:hummingbird:1nodejs26-npm-binbefore 0:26.5.1-1.5.hum10:26.5.1-1.5.hum1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSnodejs18before 18.20.8-150400.9.39.118.20.8-150400.9.39.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSnodejs20before 20.20.2-150500.11.30.120.20.2-150500.11.30.1
SUSE:Linux Enterprise Server 12 SP5-LTSSnodejs18before 18.20.8-8.44.118.20.8-8.44.1

+1

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-2026-9697Jun 17, 2026 · undici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent
    29Monitor
  • ← EarlierCVE-2026-13697Jul 29, 2026 · undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives
    36Monitor
  • Later →CVE-2026-16728Jul 29, 2026 · undici vulnerable to downstream response desynchronization via retry interceptor
    26Monitor

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 undici6.28.0Vendor (CNA)
undici undici7.29.0Vendor (CNA)
undici undici8.9.0Vendor (CNA)
azl3 nodejs 24.18.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 nodejs 24.20.0-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 nodejs 24.21.0-1 on Azure Linux 3.024.22.0-1 · Release NotesMicrosoft (MSRC)
debian:node-undici8.9.0+dfsg+~cs3.2.0-1 · Debian:14Package registry (OSV)
npm:undici6.28.0Package registry (OSV)
npm:undici7.29.0Package registry (OSV)
npm:undici8.9.0Package registry (OSV)
red hat:nodejs240:24.18.1-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-bin0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-devel0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-docs0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs260:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-bin0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-devel0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-docs0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-full-i18n0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-libs0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm0:11.17.0-1.26.5.1.1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm-bin0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:nodejs1818.20.8-8.44.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:nodejs2020.20.2-150600.3.21.1 · SUSE:Linux Enterprise Server 15 SP6-LTSSPackage registry (OSV)

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).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

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.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

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

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
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS vector

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

nvd-primary

Attack context

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

Change log

  1. 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