undici vulnerable to Denial of Service via WebSocketStream unclean close
undici's experimental WebSocketStream client crashes the whole Node.js process when a remote peer closes the TCP connection without a WebSocket close handshake. On an unclean close the internal socket-close handler calls abort on the writable stream unconditionally and discards the returned promise, but per the WHATWG Streams standard aborting a locked writable returns a promise that rejects with a TypeError. Because the application holds a writer on that writable, which is the only way to write, the rejection is never observed and Node's default unhandled-rejection behavior terminates the process. An untrusted server can therefore crash a client with a single abrupt disconnect, with no authentication and no application mistake. This affects undici versions from 7.0.0 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.
- Published
- Sep 4, 2026
- Updated
- Sep 15, 2026
- EPSS
- 0.4% · 29th percentile
- CWE
- CWE-248
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Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 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
- 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:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| nodejs | undici | cpe:2.3:a:nodejs:undici |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nodejs undici7.0.0 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
- 7.0.0 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.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | node-undici | all versions | — |
| Debian:14 | node-undici | before 8.10.2+dfsg+~cs3.2.2-1 | 8.10.2+dfsg+~cs3.2.2-1 |
| npm | undici | from 7.0.0 · before 7.29.1 | 7.29.1 |
| npm | undici | from 8.0.0 · before 8.10.2 | 8.10.2 |
| Red Hat:hummingbird:1 | grafana12.4 | before 0:12.4.10-0.2.hum1 | 0:12.4.10-0.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24 | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-bin | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-devel | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-docs | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-full-i18n | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-libs | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-npm | before 0:11.16.0-1.24.18.1.0.2.2.hum1 | 0:11.16.0-1.24.18.1.0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs24-npm-bin | before 0:24.18.1-0.2.2.hum1 | 0:24.18.1-0.2.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26 | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-bin | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-devel | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-docs | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-full-i18n | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-libs | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-npm | before 0:11.19.0-1.26.7.0.1.5.2.hum1 | 0:11.19.0-1.26.7.0.1.5.2.hum1 |
| Red Hat:hummingbird:1 | nodejs26-npm-bin | before 0:26.7.0-1.5.2.hum1 | 0:26.7.0-1.5.2.hum1 |
| Red Hat:hummingbird:1 | v8-14.6-devel | before 0:14.6.202.34-1.26.7.0.1.5.2.hum1 | 0:14.6.202.34-1.26.7.0.1.5.2.hum1 |
Same product
nodejs: all recordsOther 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-2026-84961undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool36Monitor
- CVE-2026-13697undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives36Monitor
- CVE-2026-6734undici vulnerable to cross-origin request routing via SOCKS5 proxy pool reuse35Monitor
- CVE-2026-84933undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches32Monitor
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) |
| 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) |
| 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-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) |
| red hat:nodejs24-full-i18n | 0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-libs | 0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-npm | 0:11.16.0-1.24.18.1.0.2.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-npm-bin | 0:24.18.1-0.2.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26 | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-bin | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-devel | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-docs | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-full-i18n | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-libs | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-npm | 0:11.19.0-1.26.7.0.1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-npm-bin | 0:26.7.0-1.5.2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:v8-14.6-devel | 0:14.6.202.34-1.26.7.0.1.5.2.hum1 · Red Hat:hummingbird:1 | Package 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.
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Yanhaoxireporter
- 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-2026-195340 days apartundici vulnerable to Denial of Service via unrequested WebSocket subprotocol30Monitor
- CVE-2026-1528176 days apartundici is vulnerable to Malicious WebSocket 64-bit length overflows undici parser and crashes the client30Monitor
- CVE-2026-2229176 days apartundici is vulnerable to Unhandled Exception in undici WebSocket Client Due to Invalid server_max_window_bits Validation30Monitor
- CVE-2026-850240 days apartundici vulnerable to Denial of Service via unhandled error in WebSocket permessage-deflate decompression23Monitor
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-248 · Uncaught ExceptionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- cna.openjsf.org/security-advisories.html
- github.com/nodejs/undici/security/advisories/GHSA-rx4f-c7p8-82vq
Vendor advisories and official records. Exploit/PoC links are deliberately left out.