undici vulnerable to downstream response desynchronization via retry interceptor
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. 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 malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-16728
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 02:23 UTC · Revision 1
Source evidence
undici vulnerable to downstream response desynchronization via retry interceptor
core-osv · Original sourcePublished 29 Jul 2026, 20:59 UTC
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. 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 malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.
osv:CVE-2026-16728
Complete source record
{
"id": "6b66faeb22ca9fdf62a97d9b04a051fd185342dada5dde6ee52b534b3f3a2929",
"url": "https://osv.dev/vulnerability/CVE-2026-16728",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "undici vulnerable to downstream response desynchronization via retry interceptor",
"summary": "undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. 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 malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.",
"evidence": "osv:CVE-2026-16728",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-16728",
"aliases": [
"CVE-2026-16728",
"GHSA-8xcm-r25x-g524"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/nodejs/undici",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "01a912e49a50c48009ed2639d2a457a6ec26752a"
},
{
"introduced": "1cfe0949053aac6267f11b919cee9315a27f1fd6"
},
{
"fixed": "9e38fc121d2eb26086d41c7d9379b47a6fada1c5"
},
{
"introduced": "d7fbba51772deecb830a297647456a5e9f9fec57"
},
{
"fixed": "21a8e1ed1843e74c3004a2926c12bb0ceaca6b71"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "6.28.0"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*",
"range": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.29.0"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*",
"range": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.9.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v6.27.0",
"v7.28.0",
"v8.8.0",
"v8.7.0",
"v8.6.0",
"v8.5.0",
"v6.26.0",
"v7.27.2",
"v8.4.1",
"v8.4.0",
"v7.27.1",
"v7.27.0",
"v7.26.0",
"v6.25.0",
"v8.3.0",
"v8.2.0",
"v7.25.0",
"v7.24.8",
"v8.1.0",
"v8.0.3",
"v8.0.2",
"v8.0.1",
"v8.0.0",
"v7.24.7",
"v7.24.6",
"v7.24.5",
"v7.24.4",
"v7.24.3",
"v7.24.2",
"v6.24.1",
"v6.24.0",
"v7.24.1",
"v7.24.0",
"v6.23.0",
"v7.23.0",
"v7.22.0",
"v7.21.0",
"v7.20.0",
"v7.19.2",
"v7.19.1",
"v7.19.0",
"v7.18.2",
"v7.18.1",
"v7.18.0",
"v6.22.0",
"v7.17.0",
"v7.16.0",
"v7.15.0",
"v6.21.3",
"v7.14.0",
"v7.13.0",
"v7.12.0",
"v7.11.0",
"v7.10.0",
"v6.21.2",
"v7.9.0",
"v7.8.0",
"v7.7.0",
"v7.5.0",
"v7.6.0",
"v7.4.0",
"v6.21.1",
"v7.3.0",
"v7.2.3",
"v7.2.2",
"v7.2.1",
"v7.2.0",
"v7.1.1",
"v7.1.0",
"v7.0.0",
"v6.21.0",
"v6.20.1",
"v6.20.0",
"v6.19.8",
"v6.19.7",
"v6.19.6",
"v6.19.5",
"v6.19.4",
"v6.19.3",
"v6.19.2",
"v6.19.1",
"v6.19.0",
"v6.18.2",
"v6.18.1",
"v6.18.0",
"v6.17.0",
"v6.16.1",
"v6.16.0",
"v6.15.0",
"v6.14.1",
"v6.14.0",
"v6.13.0",
"v6.12.0",
"v6.11.1",
"v6.11.0",
"v6.10.2",
"v6.10.1",
"v6.10.0",
"v6.9.0",
"v6.8.0",
"v6.7.1",
"v6.7.0",
"v6.6.2",
"v6.6.1",
"v5.28.2",
"v6.6.0",
"v6.5.0",
"v6.4.0",
"v6.3.0",
"v6.2.1",
"v6.2.0",
"v6.1.0",
"v6.0.1",
"v6.0.0",
"v5.28.1",
"v5.28.0",
"v5.27.2",
"v5.27.1",
"v5.27.0",
"v5.26.5",
"v5.26.4",
"v5.26.3",
"v5.26.2",
"v5.26.1",
"v5.26.0",
"v5.23.4",
"v5.25.3",
"v5.25.2",
"v5.25.1",
"v5.25.0",
"v5.24.0",
"v5.23.0",
"v5.22.1",
"v5.22.0",
"v5.21.2",
"v5.21.1",
"v5.21.0",
"v5.20.0",
"v5.19.1",
"v5.19.0",
"v5.18.0",
"v5.17.1",
"v5.17.0",
"v5.16.0",
"v5.15.2",
"v5.15.1",
"v5.15.0",
"v5.14.0",
"v5.13.0",
"v5.12.0",
"v5.11.0",
"v5.10.0",
"v5.9.1",
"v5.8.2",
"v5.8.1",
"v5.8.0",
"v5.7.0",
"v5.6.1",
"v5.6.0",
"v5.5.1",
"v5.5.0",
"v5.4.0",
"v5.3.0",
"v5.2.0",
"v5.1.1",
"v5.1.0",
"v5.0.0",
"v4.16.0",
"v4.15.1",
"v4.15.0",
"v4.14.1",
"v4.14.0",
"v4.13.0",
"v4.12.2",
"v4.12.0",
"v4.11.3",
"v4.11.2",
"v4.11.1",
"v4.11.0",
"v4.10.4",
"v4.10.3",
"v4.10.2",
"v4.10.1",
"v4.10.0",
"v4.9.5",
"v4.9.4",
"v4.9.3",
"v4.9.2",
"v4.9.1",
"v4.9.0",
"v4.8.2",
"v4.8.1",
"v4.8.0",
"v4.7.3",
"v4.7.2",
"v4.7.1",
"v4.7.0",
"v4.6.0",
"v4.5.1",
"v4.5.0",
"v4.4.7",
"v4.4.6",
"v4.4.5",
"v4.4.4",
"v4.4.3",
"v4.4.2",
"v4.4.1",
"v4.3.1",
"v4.3.0",
"v4.2.2",
"v4.2.1",
"v4.1.1",
"v4.1.0",
"v4.0.0",
"v4.0.0-rc.8",
"v4.0.0-rc.7",
"v4.0.0-rc.5",
"v4.0.0-rc.4",
"v4.0.0-rc.3",
"v4.0.0-rc.2",
"v4.0.0-rc.1",
"v4.0.0-alpha.5",
"v4.0.0-alpha.4",
"v4.0.0-alpha.2",
"v4.0.0-alpha.1",
"v4.0.0-alpha.0",
"v3.3.1",
"v3.3.0",
"v3.2.0",
"v3.1.0",
"v3.0.0",
"v2.1.0",
"v2.0.7",
"v2.0.6",
"v2.0.5",
"v2.0.4",
"v2.0.3",
"v2.0.2",
"v2.0.1",
"v2.0.0",
"v1.3.1",
"v1.3.0",
"v1.2.6",
"v1.2.5",
"v1.2.2",
"v1.2.1",
"v1.2.0",
"v1.1.0",
"v1.0.3",
"v1.0.2",
"v1.0.1",
"v1.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-16728.json"
}
}
],
"modified": "2026-10-28T02:30:49.056406825Z",
"provider": "osv",
"references": [
"https://cna.openjsf.org/security-advisories.html",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16728.json",
"https://github.com/nodejs/undici/security/advisories/GHSA-8xcm-r25x-g524",
"https://nvd.nist.gov/vuln/detail/CVE-2026-16728"
],
"provider_metadata": {
"cwe_ids": [
"CWE-444"
],
"cna_assigner": "openjs",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16728.json"
}
},
"related_cves": [
{
"value": "CVE-2026-16728",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 517329,
"published_at": "2026-07-29T20:59:02.314+00:00"
}