CVE-2026-16728
mediumpriority · track · 26EPSS 0.003 · 21 %ileDEEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (14)
Products and version ranges known to be affected.
- IBM WebSphere Service Registry and Repositoryall versionscert_bundDEcpe:/a:ibm:websphere_service_registry_and_repository:-
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3596IBM App Connect Enterprise: Mehrere SchwachstellenDeutsch2026-09-27csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren und um einen Cross-Site Scripting Angriff durchzuführen.
- WID-SEC-W-2026-3621IBM App Connect Enterprise: Mehrere SchwachstellenDeutsch2026-09-28csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um Informationen offenzulegen, um einen Denial of Service Angriff durchzuführen, um Daten zu manipulieren und um Sicherheitsvorkehrungen zu umgehen.
- GHSA-8xcm-r25x-g524undici vulnerable to downstream response desynchronization via retry interceptor2026-08-03ghsa · osvUS
### Impact Undici's `interceptors.retry()` 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. Applications that use `interceptors.retry()` and forward upstream response headers and bodies downstream, for example proxy or gateway applications, may emit an invalid HTTP response with a stale `Content-Length` header. This can lead to downstream response desynchronization, connection hangs, or response corruption in clients or intermediaries that rely on the forwarded framing metadata. A malicious or faulty upstream can respond to a range request with a `206 Partial Content` response such as: ```http Content-Range: bytes 0-99/300 Content-Length: 300 ``` and then send only 99 bytes before closing the socket. `interceptors.retry()` can then retry with `Range: bytes=99-99`, receive the final byte, and deliver a 100-byte body to the application while the response headers still contain `Content-Length: 300` from the first response. The bug requires `interceptors.retry()` to be enabled, an upstream that returns a partial response with a mismatched framing header, and a downstream forwarder that does not remove or recalculate `Content-Length`. ### Patches Patched in undici v6.28.0, v7.29.0, and v8.9.0. Users should upgrade to one of these versions or later. ### Workarounds - Disable `interceptors.retry()` for untrusted upstreams. - Remove or recalculate `Content-Length` before forwarding a response body assembled or transformed by Undici.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://cna.openjsf.org/security-advisories.htmlcnnvd
- https://github.com/nodejs/undici/security/advisories/GHSA-8xcm-r25x-g524cnnvd
- https://cna.openjsf.org/security-advisories.htmlenisa_euvd
- https://github.com/nodejs/undici/security/advisories/GHSA-8xcm-r25x-g524enisa_euvd
- https://cna.openjsf.org/security-advisories.htmlVendor Advisorynvd
- https://github.com/nodejs/undici/security/advisories/GHSA-8xcm-r25x-g524MitigationVendor Advisorynvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan