Bug 2553372

Summary: CVE-2026-110927 openssh: openssh: a compressed payload can expand past the maximum packet size [fedora-all]
Product: [Fedora] Fedora Reporter: Ganesh <gnaik>
Component: opensshAssignee: Dmitry Belyavskiy <dbelyavs>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: crypto-team, dbelyavs, dwalsh, jjelen, mattias.ellert, tm
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---Flags: fedora-admin-xmlrpc: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["d9cae513-2215-4c96-9f0f-c8e82c75234d"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-10-19 15:13:38 UTC 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:    
Bug Blocks: 2553037    

Description Ganesh 2026-10-15 11:10:33 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A flaw was found in OpenSSH. uncompress_buffer could keep growing the output buffer inside the inflate loop until it passed the maximum packet size. The fix returns SSH_ERR_INVALID_FORMAT once the buffer reaches PACKET_MAX_SIZE. This applies only after compression has been negotiated. The extra memory stays in that connection's process. This is not a demonstrated memory-corruption flaw, and it is a different bug and reporter from the LZ77 dictionary leak.