CVE-2026-84947

undici vulnerable to response truncation via oversized chunked responses in the dump interceptor

At a glance

Severity
LOW 3.7
EPSS
EPSS 0.20 % · percentile 9 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
openjs
NVD status
Analyzed

Description

undici's dump interceptor reads and discards a response body up to a configurable maximum size. When a response declares a Content-Length that exceeds the maximum, the interceptor aborts cleanly, but when a response has no Content-Length and is chunked, the interceptor instead signals completion early once the accumulated size reaches the maximum, without pausing or aborting the request. Because the underlying parser keeps delivering body bytes, a second completion signal fires and trips an internal assertion, which aborts the request and tears down the connection. The application is left observing a misleading successful status with an empty or truncated body while the connection has actually been disconnected. This affects undici versions from 7.1.0 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.

Scores

VersionScoreVectorScored by
CVSS 3.1LOW 3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:Nopenjs
CVSS 3.1LOW 3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NNVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary)
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NNVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
undici · undiciaffected 7.1.0 < 7.29.1 ; unaffected 7.29.1 ; affected 8.0.0 < 8.10.2 ; unaffected 8.10.2

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD