High [CVE-2026-71393] integer overflow via a malicious font file
This high-severity Red Hat Linux advisory covers CVE-2026-71393.
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Summary
GNU Emacs for Android is vulnerable to an integer overflow in sfnt_read_name_table() in src/sfnt.c. The function computes an allocation size using a 32-bit length value from a TrueType font file without overflow checking.
On 32-bit targets, a crafted font causes the calculation to wrap, resulting in an undersized heap allocation. A subsequent read() call writes beyond the buffer, causing a heap buffer overflow.
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 can lead to heap memory corruption and potential code execution.
This issue was fixed in commit d51a4722316efe0960994d371e1859099894d1ca An integer overflow vulnerability exists when processing a crafted TrueType font file, leading to an undersized memory allocation. A remote attacker can exploit this by delivering a malicious font file, which, when loaded, causes a heap buffer overflow.
Red Hat severity: Moderate — CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H). Weakness: CWE-190.
Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9 as not affected.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
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