Bug 2544477 (CVE-2026-103679)

Summary: CVE-2026-103679 tnef: Use-after-free and double-free in get_body_files() via multi-value body extraction
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in tnef. A remote attacker could exploit this vulnerability by providing a specially crafted Transport Neutral Encapsulation Format (TNEF) file containing multiple message bodies. During extraction, improper memory management triggers a use-after-free and double-free condition, causing the application to crash and resulting in a Denial of Service (DoS).
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Bug Depends On: 2544596    
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Description OSIDB Bzimport 2026-10-01 09:17:31 UTC 
A flaw was found in tnef. When a TNEF stream contains more than one MAPI RTF or HTML body value, get_body_files() allocates a single filename buffer and a single MIME-type buffer and assigns the same pointers to every generated output file, instead of a separate copy per file. Each of these files is later freed independently, producing a use-after-free followed by a double-free on the second and subsequent files. The issue was confirmed under AddressSanitizer and crashes the process when extracting a crafted TNEF stream with multiple body values; no code-execution primitive has been demonstrated.