CVE-2026-16728 (GCVE-0-2026-16728)

Vulnerability from cvelistv5 – Published: 2026-07-29 20:59 – Updated: 2026-07-30 15:18
VLAI
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.
Severity
4.8 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
References
Impacted products
Vendor Product Version
undici undici Affected: 0 , < 6.28.0 (semver)
Unaffected: 6.28.0 (semver)
Affected: 7.0.0 , < 7.29.0 (semver)
Unaffected: 7.29.0 (semver)
Affected: 8.0.0 , < 8.9.0 (semver)
Unaffected: 8.9.0 (semver)
Create a notification for this product.
Credits
samuel871211 mcollina UlisesGascon
Show details on NVD website
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