CVE-2026-71393
Heap Buffer Overflow in GNU Emacs for Android
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
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 Buffer Overflow in GNU Emacs for Android
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
- Record
CVE-2026-71393- 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:N/SI:L/SA:N - Weakness
- CWE-190
- Updated
- 2026-11-02
EUVDEUVD-2026-55258
5.3
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
- Record
EUVD-2026-55258- 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:N/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4rgf-7285-chf8
5.3
GNU Emacs for Android is vulnerable to an integer overflow in sfnt_read_name_table() in src/sfnt...
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
- Record
GHSA-4rgf-7285-chf8- 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:N/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-190
- Updated
- 2026-11-02
NVD
5.3
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
- Record
CVE-2026-71393- 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:N/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-190
- Updated
- 2026-11-02
OSV
5.3
Heap Buffer Overflow in GNU Emacs for Android
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
- Record
CVE-2026-71393- 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:N/SI:L/SA:N - Weakness
- CWE-190
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-71393
5.3
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
- Record
DEBIAN-CVE-2026-71393- 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:N/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-2026-71393
5.3
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
- Record
UBUNTU-CVE-2026-71393- 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:N/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-2026-71393 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 0.67%, the 52nd percentile. No source names a fixed version.
References
cert.pl/en/posts/2026/08/CVE-2026-71391
gnu.org/savannah-checkouts/gnu/emacs/emacs.html
git.savannah.gnu.org/cgit/emacs.git/commit?id=d51a4722316efe0960994d371e1859099894d1ca
nvd.nist.gov/vuln/detail/CVE-2026-71393
github.com/advisories/GHSA-4rgf-7285-chf8
github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71393.json