Bug 2496906 (CVE-2026-14631)

Summary:	CVE-2026-14631 webpack-dev-server: webpack-dev-server: Denial of Service via malformed headers
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	aazores, abarbaro, abrianik, alizardo, anpicker, aruklets, ataylor, bbrownin, bdettelb, brasmith, cdrage, cmah, cochase, dbruscin, dkeler, doconnor, dranck, dschmidt, dymurray, eaguilar, ebaron, ehugonne, fmariani, ggrzybek, gmalinko, gparvin, hasun, ibolton, janstey, jchui, jfula, jhe, jkoehler, jlanda, jmatthew, jmontleo, jolong, jowilson, jraez, jwong, jwon, kaycoth, kshier, ktsao, kvanderr, lchilton, lphiri, mcarlett, nboldt, nyancey, oaljalju, omaciel, ometelka, parichar, pgaikwad, pjindal, psrna, ptisnovs, rhaigner, rhel-process-autobot, rjohnson, rstepani, rushinde, sfeifer, simaishi, slucidi, sseago, stcannon, suppawar, syedriko, tasato, tcunning, teagle, thason, ttakamiy, watson-tool-maintainers, xdharmai, yfang, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in webpack-dev-server. An unauthenticated remote attacker could send a specially crafted HTTP request with a malformed Host header or a WebSocket upgrade with a malformed Origin header. This malformed input causes an uncaught exception, leading to the termination of the Node.js process and crashing the development server. This vulnerability results in a Denial of Service (DoS), impacting the availability of the development server.	Story Points:	---
Clone Of:		Environment:
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-03 18:01:24 UTC

webpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer sends either a normal HTTP request with a malformed Host header or a WebSocket upgrade to the default /ws endpoint with a malformed Origin header. The malformed value causes an uncaught exception in the host-validation path and crashes the dev server. Impact is limited to availability of the development server, no data disclosure, no code execution. Patches: upgrade to webpack-dev-server 5.2.6. Workarounds: keep the dev server bound to localhost (the default) and do not expose it to untrusted networks.