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

CVE-2026-109841: undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.25% (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 7.30.1, 8.12.2.

Low priority for now. Upgrade to undici undici 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 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its fetch() implementation verifies Subresource Integrity metadata by matching the algorithm token against a lowercase-only set, even though the SRI specification defines the token by its ASCII-lowercase form, so a valid but non-lowercase token such as an uppercase or mixed-case SHA256 is treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server returning a body that does not match the pinned digest passes the check. An attacker who controls only the response body can therefore deliver attacker-controlled bytes to an application that pinned a valid uppercase or mixed-case SRI token, with no integrity error, affecting response integrity only. The issue is fixed in undici 7.30.1 and 8.12.2, which normalize the algorithm token to ASCII lowercase before validation, and users should upgrade to one of those versions or later. As a workaround, use lowercase algorithm tokens such as sha256, sha384, or sha512 in integrity metadata.

Published
Oct 15, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 16th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 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
7.5
CNA · openjs
5.9
1.6 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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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  • No public exploit code on record
  • A fix has been released

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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

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

    • 7.30.1, 8.12.2not affected
    • 7.15.0 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 undici7.15.0 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
Debian:14node-undicibefore 8.12.2+dfsg+~cs3.2.3-18.12.2+dfsg+~cs3.2.3-1
npmundicifrom 7.15.0 · 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
Red Hat:hummingbird:1nodejs24-libsbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs24-npmbefore 0:11.19.0-1.24.21.0.1.5.hum10:11.19.0-1.24.21.0.1.5.hum1
Red Hat:hummingbird:1nodejs24-npm-binbefore 0:24.21.0-1.5.hum10:24.21.0-1.5.hum1
Red Hat:hummingbird:1nodejs26before 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-binbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-develbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-docsbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-full-i18nbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-libsbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1nodejs26-npmbefore 0:11.20.0-1.26.11.1.0.4.hum10:11.20.0-1.26.11.1.0.4.hum1
Red Hat:hummingbird:1nodejs26-npm-binbefore 0:26.11.1-0.4.hum10:26.11.1-0.4.hum1
Red Hat:hummingbird:1v8-13.6-develbefore 0:13.6.233.17-1.24.21.0.1.5.hum10:13.6.233.17-1.24.21.0.1.5.hum1
Red Hat:hummingbird:1v8-14.6-develbefore 0:14.6.202.34-1.26.11.1.0.4.hum10:14.6.202.34-1.26.11.1.0.4.hum1

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-2026-109855Oct 15, 2026 · undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
    30Monitor
  • ← EarlierCVE-2026-109383Oct 15, 2026 · undici vulnerable to TLS certificate validation bypass via dropped tls options in Agent
    36Monitor
  • Later →CVE-2026-109869Oct 15, 2026 · undici vulnerable to Denial of Service via unhandled error on excessive content-encodings
    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 undici7.30.1Vendor (CNA)
undici undici8.12.2Vendor (CNA)
debian:node-undici8.12.2+dfsg+~cs3.2.3-1 · Debian:14Package 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)
red hat:v8-14.6-devel0:14.6.202.34-1.26.11.1.0.4.hum1 · Red Hat:hummingbird:1Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 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.

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 · variant or chain candidate.

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
none
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
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-178 · Improper Handling of Case Sensitivity

CVSS vector

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. CVSS5.9 → 7.5
  2. Severitymedium → high
  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