Bug 2480684 (CVE-2026-39830)

Summary: CVE-2026-39830 golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via resource leak from unsolicited SSH responses
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: aazores, akoudelk, alcohan, amctagga, anjoseph, aoconnor, aruklets, bdettelb, bniver, cmah, crizzo, dakwon, dhanak, dkeler, doconnor, drosa, dsimansk, dymurray, eaguilar, ebaron, eborisov, eglynn, fdeutsch, flucifre, gmeno, gparvin, groman, jaharrin, jbalunas, jburrell, jeder, jjoyce, jkoehler, jmatthew, jolong, jprabhak, jpretori, jschluet, kingland, kverlaen, lball, lbragsta, lgamliel, lhh, lphiri, manissin, mbenjamin, mburns, mgarciac, mhackett, mnovotny, ngough, oramraz, pahickey, pjindal, rekumar, rfreiman, rhaigner, rhel-process-autobot, rjohnson, sausingh, sbratsla, sdawley, smullick, sostapov, stirabos, suppawar, thason, vereddy, veshanka, vkarehfa, vvoronko, watson-tool-maintainers, wenshen, whayutin, wtam, xiyuan
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in golang.org/x/crypto/ssh. A remote malicious SSH peer can exploit this by sending unsolicited global request responses, which fills an internal buffer and blocks the connection's read loop. This prevents the associated resources from being released, leading to a resource leak per connection. The consequence is a Denial of Service (DoS) for the affected system.
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:
Bug Depends On: 2490391, 2490393, 2490394, 2490395, 2490398, 2490401, 2490404, 2490407, 2490410, 2490411, 2490414, 2490415, 2490417, 2490418, 2490419, 2490421, 2490423, 2490424, 2490425, 2490427, 2490428, 2490429, 2490432, 2490433, 2490434, 2490435, 2490436, 2490438, 2490440, 2490443, 2490444, 2490445, 2490446, 2490448, 2490451, 2490452, 2490453, 2490454, 2490457, 2490459, 2490460, 2490462, 2490467, 2490469, 2490470, 2490471, 2490472, 2490473, 2490475, 2490476, 2490477, 2490480, 2490481, 2490482, 2490483, 2490484, 2490485, 2490487, 2490491, 2490492, 2490493, 2490494, 2490495, 2490496, 2490499, 2490500, 2490501, 2490392, 2490396, 2490402, 2490409, 2490416, 2490420, 2490422, 2490426, 2490430, 2490431, 2490437, 2490439, 2490441, 2490442, 2490447, 2490449, 2490456, 2490464, 2490466, 2490478, 2490479, 2490486, 2490488, 2490489, 2490490, 2490497, 2490498    
Bug Blocks:    

Description OSIDB Bzimport 2026-05-22 04:02:01 UTC
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

Comment 2 errata-xmlrpc 2026-06-24 23:49:30 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:29455 https://access.redhat.com/errata/RHSA-2026:29455

Comment 4 errata-xmlrpc 2026-07-06 04:52:34 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:35833 https://access.redhat.com/errata/RHSA-2026:35833

Comment 5 errata-xmlrpc 2026-07-07 13:00:18 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:36199 https://access.redhat.com/errata/RHSA-2026:36199

Comment 8 errata-xmlrpc 2026-07-08 15:51:09 UTC
This issue has been addressed in the following products:

  RHEM 1.0 for RHEL 9

Via RHSA-2026:36796 https://access.redhat.com/errata/RHSA-2026:36796

Comment 9 errata-xmlrpc 2026-07-09 05:14:25 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:37072 https://access.redhat.com/errata/RHSA-2026:37072

Comment 10 errata-xmlrpc 2026-07-16 14:32:08 UTC
This issue has been addressed in the following products:

  RHEM 1.1 for RHEL 10
  RHEM 1.1 for RHEL 9

Via RHSA-2026:41019 https://access.redhat.com/errata/RHSA-2026:41019