CVE-2026-71394: Heap Use of Uninitialized Memory in GNU Emacs for Android
GNU Emacs for Android improperly validates the table header input in sfntreadtabledirectory() in src/sfnt.c. Due to an incorrect comparison variable in the read-length check, a crafted font file that claims to contain more table directory entries than actually present causes the parser to return a struct with uninitialized heap memory in the table directory entries. 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 leads to the use of uninitialized heap data in subsequent table lookups, potentially resulting in information disclosure, crashes, or arbitrary memory access on 32-bit targets.
This issue is fixed after commit 7621ee1d01229d50e5c0cddea6bf0b01095a62cf
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
GNU Emacs for Androidto a version that resolves this vulnerability.Patch 7621ee1d01229d50e5c0cddea6bf0b01095a62cf
Event History
Frequently Asked Questions
What is the severity of CVE-2026-71394?
CVE-2026-71394 has a risk rating of 40, indicating a significant potential impact.
How do I fix CVE-2026-71394?
To mitigate CVE-2026-71394, update GNU Emacs for Android to the latest patched version.
What vulnerabilities does CVE-2026-71394 address?
CVE-2026-71394 addresses a heap use of uninitialized memory issue in the sfnt_read_table_directory function.
Who is affected by CVE-2026-71394?
Users of GNU Emacs for Android are directly affected by CVE-2026-71394.
What type of attack does CVE-2026-71394 enable?
CVE-2026-71394 can potentially allow attackers to exploit crafted font files to cause undefined behavior.