Bug 2561461 (CVE-2026-116591)

Summary:	CVE-2026-116591 github.com/klauspost/compress: klauspost/compress: Denial of Service via crafted zstd compressed input
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	aazores, abarbaro, abuckta, akhatavk, akoudelk, alebedev, alizardo, amctagga, anjoseph, anpicker, ansmith, anthomas, aoconnor, aos-team-art-private, aprice, asatyam, asdas, asegurap, asyoung, bbrownin, blitton, bmuthuka, bniver, bsquizza, cahl, cdrage, chfoley, cmah, cmitchel, cmyers, crizzo, dfreiber, dhanak, diagrawa, dkeler, dkuc, dnakabaa, doconnor, dpaolell, drosa, drow, dschmidt, dsimansk, dymurray, eaguilar, ebaron, eborisov, ebourniv, efried, eglynn, ehelms, elicohen, eshamard, flucifre, gbenhaim, ggainey, gmeno, gparvin, groman, gtanzill, hasun, hoberger, ibolton, ikhan, jbalunas, jbritton, jburrell, jbuscemi, jcantril, jchui, jdelft, jdobes, jfula, jhe, jhollowa, jjoyce, jlanda, jmatsuok, jmatthew, jmitchel, jmontleo, jowilson, jpasqual, jprabhak, jpretori, jsamir, jschluet, jsherril, jtolenti, jturenov, jupierce, juwatts, jvasik, kaycoth, kbempah, kgaikwad, kingland, kshier, ktsao, lball, lberk, lbragsta, lchilton, lcouzens, lgamliel, lgarciaa, lhh, ljawale, lpele, mbarnett, mbenjamin, mbiarnes, mburns, mdellweg, mgarciac, mhackett, mhulan, mkleinhe, mnovotny, mold, mrunge, msilmser, mstipich, mszuc, mwringe, nboldt, ngough, niyer, nmoumoul, nyancey, oaljalju, oezr, ometelka, orabin, osousa, pakotvan, pcreech, pgaikwad, pjindal, ppalepu, ppostler, prdhamdh, prichard, psrna, ptisnovs, pwambui, rblanco, rbobbitt, rchan, rekumar, rexwhite, rhaigner, rhel-process-autobot, rjohnson, rochandr, rojacob, rushinde, sabiswas, sakbas, sarad, sausingh, sbratsla, sbunciak, sdawley, sfeifer, sghai, sidsharm, simaishi, slakshmi, slucidi, smallamp, solenoci, sostapov, sprizend, sseago, stcannon, sthirugn, sumehta, suppawar, swoodman, syedriko, thason, tmalecek, tsze, twaugh, tzivkovi, vereddy, veshanka, vimartin, vkumar, vlaad, vvoronko, watson-tool-maintainers, wenshen, whayutin, wscales, 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 the klauspost compress library. A remote attacker can exploit this vulnerability by submitting a specially crafted Zstandard (zstd) compressed stream to an application using the library, resulting in a Denial of Service (DoS). Due to an integer handling error in the decompression logic, the decoder retains stale internal state and performs an out-of-bounds read, triggering an unhandled panic that crashes the application.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-26 22:34:53 UTC

compress provides various compression algorithms. Prior to 1.20.2, the zstd DecodeAll and streaming decoder paths can panic when a crafted two-block frame reaches huff0.ReadTable with an FSE normalized count of 32768 that readNCount stores in int16 as -32768. The wrapped count allows buildDtable to retain stale fse.Scratch decode-table state from the prior block, and nextFast then derives an out-of-range state and indexes beyond the table instead of returning a decode error. Both blocks are required to preserve and then reuse the stale state, allowing untrusted zstd input to crash an application. This issue is fixed in version 1.20.2.