CVE-2026-71394
Heap Use of Uninitialized Memory in GNU Emacs for Android
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.3
Heap Use of Uninitialized Memory in GNU Emacs for Android
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
CVE-2026-71394- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N - Weakness
- CWE-1284
- Updated
- 2026-11-02
EUVDEUVD-2026-55257
5.3
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
EUVD-2026-55257- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-jx5g-mm7r-35gq
5.3
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory()...
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
GHSA-jx5g-mm7r-35gq- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-1284
- Updated
- 2026-11-02
NVD
5.3
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
CVE-2026-71394- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-1284
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-71394
5.3
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
DEBIAN-CVE-2026-71394- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-71394
5.3
GNU Emacs for Android improperly validates the table header input in sfnt_read_table_directory() 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
- Record
UBUNTU-CVE-2026-71394- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
emacs24Ubuntu:Pro:16.04:LTS |
All versions, plus listed versions 24.5+1-1ubuntu224.5+1-1ubuntu424.5+1-1ubuntu524.5+1-1ubuntu624.5+1-1ubuntu7 Show 6 moreShow less24.5+1-6ubuntu124.5+1-6ubuntu1.124.5+1-6ubuntu1.1+esm124.5+1-6ubuntu1.1+esm224.5+1-6ubuntu1.1+esm324.5+1-6ubuntu1.1+esm4 |
None known |
xemacs21Ubuntu:16.04:LTS |
All versions, plus listed versions 21.4.22-4ubuntu321.4.22-14ubuntu1 |
None known |
xemacs21-packagesUbuntu:16.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.2-2 |
None known |
emacs25Ubuntu:Pro:18.04:LTS |
All versions, plus listed versions 25.2+1-625.2+1-6ubuntu0.1~esm2 |
None known |
xemacs21Ubuntu:18.04:LTS |
All versions, plus listed versions 21.4.24-4ubuntu121.4.24-5ubuntu1 |
None known |
xemacs21-packagesUbuntu:18.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.2-4 |
None known |
emacsUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1:26.3+1-1ubuntu11:26.3+1-1ubuntu21:26.3+1-1ubuntu2+esm11:26.3+1-1ubuntu2+esm2 |
None known |
xemacs21Ubuntu:20.04:LTS |
All versions, plus listed versions 21.4.24-8build121.4.24-9 |
None known |
xemacs21-packagesUbuntu:20.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.2-42009.02.17.dfsg.2-5 |
None known |
xemacs21Ubuntu:22.04:LTS |
All versions, plus listed versions 21.4.24-9ubuntu2 |
None known |
Show 11 moreShow less
| Package | Affected | Fixed |
|---|---|---|
xemacs21-packagesUbuntu:22.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.2-5 |
None known |
emacsUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 1:27.1+1-3ubuntu31:27.1+1-3ubuntu51:27.1+1-3ubuntu5.11:27.1+1-3ubuntu5.21:27.1+1-3ubuntu5.2+esm1 |
None known |
xemacs21Ubuntu:24.04:LTS |
All versions, plus listed versions 21.4.24-1221.4.24-12build221.4.24-12build3 |
None known |
xemacs21-packagesUbuntu:24.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.3-22009.02.17.dfsg.3-3 |
None known |
emacsUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 1:29.1+1-5ubuntu11:29.2+1-1ubuntu11:29.2+1-2ubuntu41:29.3+1-1ubuntu21:29.3+1-1ubuntu2+esm11:29.3+1-1ubuntu2+esm31:29.3+1-1ubuntu2+esm4 |
None known |
emacsUbuntu:26.10 |
All versions, plus listed versions 1:30.2+1-2ubuntu11:30.2+1-6ubuntu11:30.2+1-11ubuntu1 |
None known |
xemacs21Ubuntu:26.10 |
All versions, plus listed versions 21.4.24-12build3 |
None known |
xemacs21-packagesUbuntu:26.10 |
All versions, plus listed versions 2009.02.17.dfsg.3-3build1 |
None known |
xemacs21Ubuntu:26.04:LTS |
All versions, plus listed versions 21.4.24-12build3 |
None known |
xemacs21-packagesUbuntu:26.04:LTS |
All versions, plus listed versions 2009.02.17.dfsg.3-32009.02.17.dfsg.3-3build1 |
None known |
emacsUbuntu:Pro:26.04:LTS |
All versions, plus listed versions 1:30.1+1-9ubuntu11:30.2+1-1ubuntu21:30.2+1-2ubuntu11:30.2+1-2ubuntu1+esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-71394 is a medium vulnerability (CVSS 5.3) in Gnu Emacs, published August 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 38th percentile. No source names a fixed version.