Bug 2540008

Summary: CVE-2026-95622 ModemManager: ModemManager: Reachable assertion in Cell Broadcast encoding parse causes denial of service [fedora-all]
Product: [Fedora] Fedora Reporter: Ganesh <gnaik>
Component: ModemManagerAssignee: Davide Cavalca <davide>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: bgalvani, davide, lkundrak, max, tao-j, thom311
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["028257dc-246d-47f9-986b-c9c631677eca"]}
Fixed In Version: Doc Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2540006    

Description Ganesh 2026-09-24 10:42:47 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 ModemManager. When parsing a Cell Broadcast Message, some 3GPP data-coding-scheme values (8-bit and reserved character sets) are not handled. The process hits a reachable assertion and aborts. An attacker who can deliver a crafted Cell Broadcast PDU over the radio network, or via a modem AT channel, can cause ModemManager to exit. Repeated aborts can exhaust systemd's default start limit and leave the service failed.