Bug 2528754 (CVE-2026-84947)

Summary: CVE-2026-84947 undici: Undici: Response truncation and connection termination
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: abarbaro, akhatavk, alizardo, aos-team-art-private, asdas, ataylor, cdrage, csuconic, dbruscin, dpaolell, dschmidt, eborisov, ehugonne, gbenhaim, gtanzill, gtully, jbuscemi, jchui, jdelft, jhe, jlanda, jsherman, jupierce, kshier, ktsao, kvanderr, lball, lchilton, lgarciaa, mbiarnes, mstipich, nboldt, ngough, niyer, oaljalju, ppalepu, ppostler, prdhamdh, psrna, rexwhite, rgemmell, rgodfrey, rhel-process-autobot, rushinde, sdawley, sfeifer, sghai, sidsharm, simaishi, stcannon, sthirugn, suppawar, tbish, tlavocat, twaugh, veshanka, vlaad, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in undici, a Node.js HTTP/1.1 client. When the dump interceptor processes oversized chunked responses that do not declare a Content-Length, it prematurely signals completion. This causes the application to receive an incomplete or empty response body, while the network connection is unexpectedly closed. This issue can lead to applications processing partial data or encountering unexpected connection disruptions.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2540151, 2540152, 2540149, 2540150    
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Description OSIDB Bzimport 2026-09-04 17:19:10 UTC 
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.