Bug 2556421 (CVE-2026-113721)

Summary:	CVE-2026-113721 virtualenv: virtualenv: Arbitrary file overwrite via insecure symlink handling
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, anpicker, anthomas, aos-team-art-private, aprice, asdas, cmyers, dnakabaa, dpaolell, dschmidt, ehelms, gbenhaim, ggainey, hasun, ikhan, jdelft, jdobes, jfula, jlanda, jmitchel, jowilson, jpasqual, jsamir, jupierce, juwatts, jwong, kaycoth, kgaikwad, kshier, lcouzens, lgarciaa, mbiarnes, mdellweg, mhulan, niyer, nmoumoul, nyancey, oezr, omaciel, ometelka, orabin, osousa, pcreech, ppalepu, ppostler, prdhamdh, prwatson, ptisnovs, rbobbitt, rchan, sdawley, sghai, sidsharm, simaishi, smallamp, stcannon, suppawar, syedriko, tmalecek, ttakamiy, twaugh, vlaad, xdharmai, yguenane, zzhou
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in virtualenv. A local attacker can exploit this issue by pre-creating symbolic or hard links in a destination directory before an environment is set up. Because virtualenv does not properly check or replace existing links when writing configuration and activation files, it can follow these links and write data outside the intended folder. This issue allows an attacker to create or overwrite arbitrary files with the privileges of the invoking user.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-10-20 20:02:38 UTC

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, ViaTemplateActivator._generate() removes an existing output only when Path.exists() is true, allowing a dangling symlink to survive and redirect generated activation content, while PyEnvCfg.write() opens pyvenv.cfg without first replacing an existing symbolic or hard link. Another local account that prepares final entries inside the destination can therefore cause environment creation to create or overwrite files outside the requested tree with constrained virtualenv-generated content and the invoking user's permissions. The destination parent must remain controlled by the environment owner during creation; concurrent parent-directory replacement is a separate concern. This issue is fixed in version 21.14.9.