Bug 2513086 (CVE-2026-71392)

Summary: CVE-2026-71392 emacs: integer overflow via a malicious font file
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in GNU Emacs, specifically in GNU Emacs for Android. An integer overflow can occur when a specially crafted font file is processed on 32-bit systems due to an unguarded addition during memory allocation. This can cause an undersized heap allocation and subsequently a heap-based buffer overflow, resulting in memory corruption and a denial of service.
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Description OSIDB Bzimport 2026-08-10 10:31:58 UTC
GNU Emacs for Android is vulnerable to an integer overflow in the sfnt_read_cmap_format_12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. An attacker can deliver a malicious font file via email, EWW (Emacs Web Wowser), or documents with custom faces, causing Emacs to load it. This results in heap memory corruption that can lead to code execution.


This issue was fixed in commit c4e20777c26548722a37b03db93243e83a0d6188