undici vulnerable to Denial of Service via unhandled error on excessive content-encodings
undici is an HTTP client library for Node.js. In versions 6.23.0 through 6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch() implementation crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses because of a content-encoding limit, but it created the internal response stream before that check and returned without attaching an error listener or aborting the request, so the early close surfaces a content-length mismatch on the orphaned stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection, resulting in a denial of service. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. There is no workaround.
CVE-2026-109869
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-109869
undici
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "undici",
"product": "undici",
"versions": [
{
"status": "affected",
"version": "6.23.0",
"lessThan": "6.29.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.29.1",
"versionType": "semver"
},
{
"status": "affected",
"version": "7.18.0",
"lessThan": "7.30.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.30.1",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.0.0",
"lessThan": "8.12.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "8.12.2",
"versionType": "semver"
}
],
"packageURL": "pkg:npm/undici",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-109869
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #34421 · Revision 1
- Added to Heist Feed
- Publisher date