Bug 2502730 (CVE-2026-6949)

Summary: CVE-2026-6949 samba: TSIG packet with crafted name compression can crash DNS server
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in Samba's internal DNS server when processing TSIG-signed DNS packets containing compressed names. Incorrect size calculations while determining the portion of the DNS packet covered by the TSIG signature can result in an integer underflow, leading to an out-of-bounds memory write during packet processing. A remote attacker can send a specially crafted TSIG-signed DNS packet to cause the DNS server to terminate unexpectedly.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2509257    
Bug Blocks:    
Deadline: 2026-07-28   

Description OSIDB Bzimport 2026-07-20 11:06:39 UTC
Incorrect size calculations when a TSIG record contains compressed names can lead to a large out-of-bounds write causing the server to crash.