Bug 2453496 (CVE-2026-4800)

Summary: CVE-2026-4800 lodash: lodash: Arbitrary code execution via untrusted input in template imports
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: aadhikar, aazores, abarbaro, abokovoy, abrianik, abuckta, adudiak, akostadi, alcohan, alizardo, amasferr, amctagga, anjoseph, anpicker, anthomas, aoconnor, aschwart, asoldano, bbaranow, bbrownin, bdettelb, bmaxwell, bniver, boliveir, bparees, brasmith, bsmejkal, bstansbe, caswilli, chfoley, cmah, cmyers, cochase, dbosanac, dhanak, dkuc, dlofthou, dmayorov, dnakabaa, doconnor, dranck, drosa, dschmidt, dymurray, eaguilar, ebaron, eborisov, ehelms, erezende, ewittman, fdeutsch, flucifre, frenaud, ftrivino, ggainey, ggrzybek, gmalinko, gmeno, gotiwari, gparvin, groman, hasun, ibek, ibolton, istudens, ivassile, iweiss, jachapma, janstey, jbalunas, jchui, jfula, jgrulich, jhe, jhorak, jkoehler, jlanda, jlledo, jmatthew, jmontleo, jolong, jowilson, jprabhak, jraez, jreimann, jrokos, juwatts, jwong, kaycoth, kbempah, kshier, ktsao, lball, lchilton, lcouzens, lphiri, manissin, mbarnett, mbenjamin, mdessi, mhackett, mhulan, mnovotny, mosmerov, mposolda, mreynolds, mrizzi, mstipich, msvehla, mvyas, mwringe, nboldt, ngough, nipatil, nmoumoul, nwallace, nyancey, oaljalju, omaciel, ometelka, orabin, oramraz, osousa, pahickey, pantinor, parichar, pberan, pcattana, pcreech, pdelbell, pesilva, pgaikwad, pjindal, pmackay, progier, psrna, ptisnovs, rchan, rexwhite, rgodfrey, rhaigner, rjohnson, rkubis, rmartinc, rstancel, rstepani, sausingh, sdawley, sdoran, sfeifer, simaishi, slucidi, smaestri, smallamp, smcdonal, smullick, snegrini, solenoci, sostapov, spichugi, sseago, ssilvert, stcannon, sthirugn, sthorger, stirabos, swoodman, syedriko, tasato, tbordaz, teagle, thason, thjenkin, tmalecek, tpopela, tsedmik, ttakamiy, vashirov, vdosoudi, vereddy, veshanka, vmuzikar, wtam, xdharmai, yguenane
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in lodash. The fix for CVE-2021-23337 added validation for the variable option in _.template but did not apply the same validation to options.imports key names. Both paths flow into the same Function() constructor sink. Additionally, _.template uses assignInWith to merge imports, which enumerates inherited properties via for..in. If Object.prototype has been polluted by any other vector, the polluted keys are copied into the imports object and passed to Function().
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2453972, 2453974, 2453976, 2453977, 2453978, 2453979, 2453980, 2453981, 2453982, 2453983, 2453984, 2453986, 2453987, 2453988, 2453989, 2453990, 2453991, 2453992, 2453993, 2453995, 2453999, 2454001, 2454004, 2454005, 2454006, 2454007, 2454008, 2454009, 2454010, 2454011, 2454012, 2454014, 2454015, 2454016, 2454019, 2454020, 2454021, 2454022, 2454023, 2454024, 2454025, 2454026, 2454027, 2454028, 2454029, 2454031, 2454035, 2454036, 2454037, 2454038, 2454039, 2454041, 2454042, 2454043, 2454044, 2454046, 2454048, 2454049, 2454050, 2454051, 2454053, 2454054, 2454056, 2454057, 2454058, 2453973, 2453975, 2453985, 2453994, 2453997, 2454003, 2454013, 2454017, 2454018, 2454033, 2454034, 2454040, 2454052, 2454055    
Bug Blocks:    

Description OSIDB Bzimport 2026-03-31 20:01:47 UTC 
Impact:

The fix for CVE-2021-23337 (https://github.com/advisories/GHSA-35jh-r3h4-6jhm) added validation for the variable option in _.template but did not apply the same validation to options.imports key names. Both paths flow into the same Function() constructor sink.

When an application passes untrusted input as options.imports key names, an attacker can inject default-parameter expressions that execute arbitrary code at template compilation time.

Additionally, _.template uses assignInWith to merge imports, which enumerates inherited properties via for..in. If Object.prototype has been polluted by any other vector, the polluted keys are copied into the imports object and passed to Function().

Patches:

Users should upgrade to version 4.18.0.

Workarounds:

Do not pass untrusted input as key names in options.imports. Only use developer-controlled, static key names.