Skip to content
Noroxi
NVD / CVE Program· CNA openjs

CVE-2026-84890: undici vulnerable to Denial of Service via unbounded decompression of compressed responses

Noroxi assessment

Priority: Monitor (action score 23/100)

  • 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: 0.41% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • 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 decompress interceptor decompresses response bodies according to the untrusted Content-Encoding header. While the number of content-encoding layers is capped, the total decompressed output size is unbounded and there is no configuration option to limit it. A malicious or faulty upstream can therefore return a small compressed payload, a compression bomb, that expands to hundreds of megabytes or more in client memory, an asymmetric resource consumption that can exhaust memory and crash the process. This affects undici versions from 7.15.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.

MediumCVSS 5.9 · v3.1—No exploit Fix available
Published
Sep 4, 2026
Updated
Sep 11, 2026
EPSS
0.4% · 35th percentile

Report tools

JSON

Action score

23

Monitor

Low priority for now.

CVSS
23 / 40 · 5.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · openjs
5.9
NVD has not scored this yet; the score shown is the CNA’s.

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-84890

When you'll hear from us

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for nodejs records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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 undici7.15.0 and later · before 7.29.1
  • nodejs undici8.0.0 and later · before 8.10.2

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
    • 7.15.0 and later · before 7.29.1affected · semver
    • 8.0.0 and later · before 8.10.2affected · 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 8.10.2+dfsg+~cs3.2.2-18.10.2+dfsg+~cs3.2.2-1
npmundicifrom 7.15.0 · before 7.29.17.29.1
npmundicifrom 8.0.0 · before 8.10.28.10.2
openSUSE:Leap 16.0pi-coding-agentbefore 1.0.4-bp160.1.11.0.4-bp160.1.1
Red Hat:hummingbird:1grafana12.4before 0:12.4.10-0.2.hum10:12.4.10-0.2.hum1
Red Hat:hummingbird:1nodejs24before 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-binbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-develbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-docsbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-full-i18nbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-libsbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs24-npmbefore 0:11.16.0-1.24.18.1.0.2.2.hum10:11.16.0-1.24.18.1.0.2.2.hum1
Red Hat:hummingbird:1nodejs24-npm-binbefore 0:24.18.1-0.2.2.hum10:24.18.1-0.2.2.hum1
Red Hat:hummingbird:1nodejs26before 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-binbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-develbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-docsbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-full-i18nbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-libsbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1nodejs26-npmbefore 0:11.19.0-1.26.7.0.1.5.2.hum10:11.19.0-1.26.7.0.1.5.2.hum1
Red Hat:hummingbird:1nodejs26-npm-binbefore 0:26.7.0-1.5.2.hum10:26.7.0-1.5.2.hum1
Red Hat:hummingbird:1v8-14.6-develbefore 0:14.6.202.34-1.26.7.0.1.5.2.hum10:14.6.202.34-1.26.7.0.1.5.2.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-2026-18540Sep 4, 2026 · undici vulnerable to downstream response splitting via retry interceptor
    14Monitor
  • ← EarlierCVE-2026-19534Sep 4, 2026 · undici vulnerable to Denial of Service via unrequested WebSocket subprotocol
    30Monitor
  • Later →CVE-2026-109855Oct 15, 2026 · undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
    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 undici7.29.1Vendor (CNA)
undici undici8.10.2Vendor (CNA)
debian:node-undici8.10.2+dfsg+~cs3.2.2-1 · Debian:14Package registry (OSV)
npm:undici7.29.1Package registry (OSV)
npm:undici8.10.2Package registry (OSV)
opensuse:pi-coding-agent1.0.4-bp160.1.1 · openSUSE:Leap 16.0Package registry (OSV)
red hat:grafana12.40:12.4.10-0.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs240:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-bin0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-devel0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-docs0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-full-i18n0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-libs0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-npm0:11.16.0-1.24.18.1.0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs24-npm-bin0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs260:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-bin0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-devel0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-docs0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-full-i18n0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-libs0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm0:11.19.0-1.26.7.0.1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nodejs26-npm-bin0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:v8-14.6-devel0:14.6.202.34-1.26.7.0.1.5.2.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.

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.

  • CVE-2026-10992441 days apartundici vulnerable to Denial of Service via unbounded memory in the EventSource parser
    30Monitor
  • CVE-2026-22036233 days apartUndici has an unbounded decompression chain in HTTP responses on Node.js Fetch API via Content-Encoding leads to resource exhaustion
    30Monitor
  • CVE-2026-2581176 days apartundici is vulnerable to Unbounded Memory Consumption in in Undici's DeduplicationHandler via Response Buffering leads to DoS
    23Monitor

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

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

nvd-secondary

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